Gentoo Linux/x86 HandbookContent:
A. Installing Gentoo1. About the Gentoo Linux InstallationFirst of all, welcome to Gentoo. You are about to enter the world of choices and performance. Gentoo is all about choices. When installing Gentoo, this is made clear to you several times -- you can choose how much you want to compile yourself, how to install Gentoo, what system logger you want, etc. Gentoo is a fast, modern metadistribution with a clean and flexible design. Gentoo is built around free software and doesn't hide from its users what is beneath the hood. Portage, the package maintenance system which Gentoo uses, is written in Python, meaning you can easily view and modify the source code. Gentoo's packaging system uses source code (although support for precompiled packages is included too) and configuring Gentoo happens through regular textfiles. In other words, openness everywhere. It is very important that you understand that choices are what makes Gentoo run. We try not to force you onto anything you don't like. If you feel like we do, please bugreport it. How is the Installation Structured? The Gentoo Installation can be seen as a 10-step procedure, corresponding to chapters 2 - 11. Every step results in a certain state:
When you are given a certain choice, we try our best to explain what the pros and cons are. We will continue then with a default choice, identified by "Default: " in the title. The other possibilities are marked by "Alternative: ". Do not think that the default is what we recommend. It is however what we believe most users will use. Sometimes you can pursue an optional step. Such steps are marked as "Optional: " and are therefore not needed to install Gentoo. However, some optional steps are dependant on a previous decision you made. We will inform you when this happens, both when you make the decision, and right before the optional step is described. You can install Gentoo in many different ways. You can download and install from one of our LiveCDs (installation CDs), from an existing distribution, from a bootable CD (such as Knoppix), from a netbooted environment, from a rescue floppy, etc. This document covers the installation using one of our LiveCDs or, in certain cases, NetBooting. For help on the other installation approaches, please read our Alternative Installation Guide. We also provide a Gentoo Installation Tips & Tricks document that might be useful to read as well. If you feel that the current installation instructions are too elaborate, feel free to use our Quick Installation Guide available from our Documentation Resources if your architecture has such a document available. You also have several possibilities: you can compile your entire system from scratch or install prebuilt packages to have your Gentoo environment up and running in no time. And of course you have intermediate solutions in which you don't compile everything but start from a semi-ready system. If you find a problem in the installation (or in the installation documentation), please check the errata from our Gentoo Release Engineering Project, visit our bugtracking system and check if the bug is known. If not, please create a bugreport for it so we can take care of it. Do not be afraid of the developers who are assigned to (your) bugs -- they generally don't eat people. Note though that, although the document you are now reading is architecture-specific, it will contain references to other architectures as well. This is due to the fact that large parts of the Gentoo Handbook use source code that is common for all architectures (to avoid duplication of efforts and starvation of development resources). We will try to keep this to a minimum to avoid confusion. If you are uncertain if the problem is a user-problem (some error you made despite having read the documentation carefully) or a software-problem (some error we made despite having tested the installation/documentation carefully) you are free to join #gentoo on irc.freenode.net. Of course, you are welcome otherwise too :) If you have a question regarding Gentoo, check out our Frequently Asked Questions, available from the Gentoo Documentation. You can also view the FAQs on our forums. If you can't find the answer there ask on #gentoo, our IRC-channel on irc.freenode.net. Yes, several of us are freaks who sit on IRC :-) What is the Gentoo Reference Platform? The Gentoo Reference Platform, from now on abbreviated to GRP, is a snapshot of prebuilt packages users (that means you!) can install during the installation of Gentoo to speed up the installation process. The GRP consists of all packages required to have a fully functional Gentoo installation. They are not just the ones you need to have a base installation up to speed in no time, but all lengthier builds (such as KDE, xorg-x11, GNOME, OpenOffice, Mozilla, ...) are available as GRP packages too. However, these prebuilt packages aren't maintained during the lifetime of the Gentoo distribution. They are snapshots released at every Gentoo release and make it possible to have a functional environment in a short amount of time. You can then upgrade your system in the background while working in your Gentoo environment. How Portage Handles GRP Packages Your Portage tree - the collection of ebuilds (files that contain all information about a package, such as its description, homepage, sourcecode URLs, compilation instructions, dependencies, etc.) - must be synchronised with the GRP set: the versions of the available ebuilds and their accompanying GRP packages must match. For this reason you will have to install a Portage snapshot instead of synchronising Portage with the latest available tree if you want to use the GRP installation method. Not all architectures provide GRP packages. That doesn't mean GRP isn't supported on the other architectures, but it means that we don't have the resources to build and test the GRP packages. At present we provide GRP packages for the following architectures:
If your architecture (or subarchitecture) isn't on this list, you are not able to opt for a GRP installation. Now that this introduction is over, let's continue with Choosing the Right Installation Medium. 2. Choosing the Right Installation MediumBefore we start, we first list what hardware requirements you need to successfully install Gentoo on your box.
Still interested in trying out Gentoo? Well, then it is now time to choose the installation medium you want to use. Yes, you have the choice, no, they are not all equal, and yes, the result is always the same: a Gentoo base system. The installation media we will describe are:
Every single media has its advantages and disadvantages. We will list the pros and cons of every medium so you have all the information to make a justified decision. But before we continue, let's explain our three-stage installation. Gentoo Linux can be installed using one of three stage tarball files. The one you choose depends on how much of the system you want to compile yourself. The stage1 tarball is used when you want to bootstrap and build the entire system from scratch. The stage2 tarball is used for building the entire system from a bootstrapped "semi-compiled" state. The stage3 tarball already contains a basic Gentoo Linux system that has been built for you. As we will explain later, you can also install Gentoo without compiling anything (except your kernel and some optional packages). If you want this, you have to use a stage3 tarball. Now what stage do you have to choose? Starting from a stage1 allows you to have total control over the optimization settings and optional build-time functionality that is initially enabled on your system. This makes stage1 installs good for power users who know what they are doing. It is also a great installation method for those who would like to know more about the inner workings of Gentoo Linux. A stage1 installation can only be performed when you have a working Internet connection.
Stage2 installs allow you to skip the bootstrap process and doing this is fine if you are happy with the optimization settings that we chose for your particular stage2 tarball. A stage2 installation can only be performed when you have a working Internet connection.
Choosing to go with a stage3 allows for the fastest install of Gentoo Linux, but also means that your base system will have the optimization settings that we chose for you (which to be honest, are good settings and were carefully chosen to enhance performance while maintaining stability). stage3 is also required if you want to install Gentoo using prebuilt packages or without a network connection.
You might be interested to know that, if you decide to use different optimization settings after having installed Gentoo, you will be able to recompile your entire system with the new optimization settings. Now take a look at the available installation media. The Gentoo LiveCDs are bootable CDs which contain a self-sustained Gentoo environment. They allow you to boot Linux from the CD. During the boot process your hardware is detected and the appropriate drivers are loaded. They are maintained by Gentoo developers. All LiveCDs allow you to boot, set up networking, initialize your partitions and start installing Gentoo from the Internet. However, some LiveCDs also contain all necessary source code so you are able to install Gentoo without a working network configuration. Now what do these LiveCDs contain? This is a small, no-nonsense, bootable CD which sole purpose is to boot the system, prepare the networking and continue with the Gentoo installation. It does not contain any stages (or, in some cases, a single stage1 file), source code or precompiled packages. For example the x86 variant of this LiveCD can be found in the universal subdirectory and is called install-x86-minimal-2004.2.iso.
Gentoo's Universal LiveCD is a bootable CD suitable to install Gentoo without networking. It contains a stage1 and several stage3 tarballs (optimized for the individual subarchitectures). For example the x86 variant of this CD is called install-x86-universal-2004.2.iso and can be found in the universal subdirectory. If you take a closer look into releases/x86/2004.2 you will see that we also provide Gentoo Package CDs (in the packagecd/) directory. This CD (which isn't bootable) only contains precompiled packages and can be used to install software after a succesfull Gentoo Installation. To install Gentoo, you only need the Universal LiveCD, but if you want OpenOffice.org, Mozilla, KDE, GNOME etc. without having to compile every single one of them, you need the Packages CD too. For example the i686 (a subarchitecture of x86) Packages CD is called packages-i686-2004.2.iso and can be found in the appropriate subdirectory (i686). You only need the Packages CD if you want to perform a stage3 with GRP installation.
2.c. Download, Burn and Boot a Gentoo LiveCD Downloading and Burning the LiveCDs You have chosen to use a Gentoo LiveCD. We'll first start by downloading and burning the chosen LiveCD. We previously discussed the several available LiveCDs, but where can you find them? You can download any of the LiveCDs (and, if you want to, a Packages CD as well) from one of our mirrors. The LiveCDs are located in the releases/x86/2004.2/livecd directory; the Packages CDs are located in the releases/x86/2004.2/packagecd directory. Inside that directory you'll find so-called ISO-files. Those are full CD images which you can write on a CD-R. In case you wonder if your downloaded file is corrupted or not, you can check its MD5 checksum and compare it with the MD5 checksum we provide (such as install-x86-minimal-2004.2.iso.md5). You can check the MD5 checksum with the md5sum tool under Linux/Unix or md5sum for Windows. Another way to check the validity of the downloaded file is to use GnuPG to verify the cryptographic signature that we provide (the file ending with .asc). Download the signature file and obtain the public key:
Now verify the signature:
To burn the downloaded ISO(s), you have to select raw-burning. How you do this is highly program-dependent. We will discuss cdrecord and K3B here; more information can be found in our Gentoo FAQ.
Once you have burned your installation CDs, it is time to boot them. Remove all CDs from your CD drives, reboot your system and enter the BIOS. This is usually done by hitting DEL, F1 or ESC, depending on your BIOS. Inside the BIOS, change the boot order so that the CD-ROM is tried before the hard disk. This is often found under "CMOS Setup". If you don't do this, your system will just reboot from the hard disk, ignoring the CD-ROM. Now place the installation CD in the CD-ROM drive (duh) and reboot. You should see a fancy boot screen with the Gentoo Linux logo on it. At this screen, you can hit Enter to begin the boot process with the default boot options, or boot the LiveCD with custom boot options by specifying a kernel followed by boot options and then hitting Enter. Specifying a kernel? Yes, we provide several kernels on our LiveCDs. The default one is gentoo. Other kernels are smp, which activates support for multi-cpu systems and the -nofb variants which disable framebuffer. It is recommended that you select the gentoo or gentoo-nofb kernels if you want to install Gentoo Linux with a 2.4 kernel or smp or smp-nofb if you want to install Gentoo Linux with a 2.6 kernel. Otherwise you might run into compatibility issues. Below you'll find a short overview on the available kernels:
You can also provide kernel options. They represent optional settings you can (de)activate at will. The following list is the same as the one you receive when you press F2 at the bootscreen.
Now boot your CD, select a kernel (if you are not happy with the default gentoo kernel) and boot options. As an example, we show you how to boot the gentoo kernel, with dopcmcia as kernel parameters:
You will then be greeted with another boot screen and progress bar. Once the boot process completes, you will be automatically logged in to the "Live" Gentoo Linux as "root", the super user. You should have a root ("#") prompt on the current console and can also switch to other consoles by pressing Alt-F2, Alt-F3 and Alt-F4. Get back to the one you started on by pressing Alt-F1. If you are installing Gentoo on a system with a non-US keyboard, make sure you boot the LiveCD with the dokeymap boot option. Now continue with Extra Hardware Configuration. When the Live CD boots, it tries to detect all your hardware devices and loads the appropriate kernel modules to support your hardware. In the vast majority of cases, it does a very good job. However, in some cases (the SPARC LiveCDs don't even do autodetection), it may not auto-load the kernel modules you need. If the PCI auto-detection missed some of your system's hardware, you will have to load the appropriate kernel modules manually. In the next example we try to load the 8139too module (support for certain kinds of network interfaces):
Optional: Tweaking Hard Disk Performance If you are an advanced user, you might want to tweak the IDE hard disk performance using hdparm. With the -tT options you can test the performance of your disk (execute it several times to get a more precise impression):
To tweak, you can use any of the following examples (or experiment yourself) which use /dev/hda as disk (substitute with your disk):
If you plan on giving other people access to your installation environment or you want to chat using irssi without root privileges (for security reasons), you need to create the necessary user accounts and change the root password. To change the root password, use the passwd utility:
To create a user account, we first enter their credentials, followed by its password. We use useradd and passwd for these tasks. In the next example, we create a user called "john".
You can change your user id from root to the newly created user by using su:
Optional: Viewing Documentation while Installing If you want to view the Gentoo Handbook (either from-CD or online) during the installation, make sure you have created a user account (see Optional: User Accounts). Then press Alt-F2 to go to a new terminal and log in. If you want to view the documentation on the CD you can immediately run links2 to read it:
However, it is preferred that you use the online Gentoo Handbook as it will be more recent than the one provided on the CD. You can view it using links2 as well, but only after having completed the Configuring your Network chapter (otherwise you won't be able to go on the Internet to view the document):
You can go back to your original terminal by pressing Alt-F1. Optional: Starting the SSH Daemon If you want to allow other users to access your computer during the Gentoo installation (perhaps because those users are going to help you install Gentoo, or even do it for you), you need to create a user account for them and perhaps even provide them with your root password (only do that if you fully trust that user). To fire up the SSH daemon, execute the following command:
To be able to use sshd, you first need to set up your networking. Continue with the chapter on Configuring your Network. 3. Configuring your Network3.a. You can do without, but... Depending on the medium you chose to install Gentoo from, you may or may not continue without networking (and Internet). No, we are not playing with your mind =) Generally you will need to set up networking (and Internet). However, Gentoo also provides the possibility to install without a network connection. This exception is only possible with the Gentoo Universal LiveCDs. Installing Gentoo from the Internet results in a fully updated Gentoo Installation. You'll have an installation based on the most recent Portage tree (which is the collection of packages we provide together with the tools to manage your software). This is also the reason why a network-installation is preferred. However, some people cannot or do not want to install Gentoo on a system with a running Internet connection. If you are in this situation you will need to use a Gentoo Universal LiveCD. This LiveCD includes the source code, a snapshot of the Portage tree and the tools to install a Gentoo base-system and beyond. This method comes at a price: You won't have the very latest software, although differences will be minimal. If you want to follow this networkless installation you have to use such a Universal LiveCD, skip the rest of this chapter and continue with Preparing the Disks. Otherwise, continue with the networking configuration sections below. If you access the Internet through a proxy, you might need to set up proxy information during the installation. It is very easy to define a proxy: you just need to define a variable which contains the proxy server information. In most cases, you can just define the variables using the server hostname. As an example, we assume the proxy is called proxy.gentoo.org and the port is 8080.
If your proxy requires a username and password, you should use the following syntax for the variable:
For instance, for HTTP proxying with our previous proxy server and a username of "john" with a password of "f00b_r" one would use:
3.b. Automatic Network Detection If your system is plugged into an Ethernet network with a DHCP server, it is very likely that your networking configuration has already been set up automatically for you. If so, you should be able to take advantage of the many included network-aware commands on the LiveCD such as ssh, scp, ping, irssi, wget and links, among others. If networking has been configured for you, the /sbin/ifconfig command should list some network interfaces besides lo, such as eth0:
You may want to try pinging your ISP's DNS server (found in /etc/resolv.conf) and a Web site of choice, just to make sure that your packets are reaching the net, DNS name resolution is working correctly, etc..
Are you able to use your network? If so, you can skip the rest of this section and continue with Preparing the Disks. If not, bad luck, you'll have to work on it a bit more. 3.c. Automatic Network Configuration If the network doesn't work immediately, some installation media allow you to use net-setup (for regular networks) or adsl-setup (for ADSL-users) or pptp (for PPTP-users - only available on x86). If your installation medium does not contain any of these tools or your network doesn't function yet, continue with Manual Network Configuration.
The simplest way to set up networking if it didn't get configured automatically is to run the net-setup script:
net-setup will ask you some questions about your network environment. When all is done, you should have a working network connection. Test your network connection as stated before. If the tests are positive, congratulations! You are now ready to install Gentoo. Skip the rest of this section and continue with Preparing the Disks. If your network still doesn't work, continue with Manual Network Configuration. Assuming you need PPPoE to connect to the internet, the LiveCD (any version) has made things easy for you by including rp-pppoe. Use the provided adsl-setup script to configure your connection. You will be prompted for the ethernet device that is connected to your adsl modem, your username and password, the IPs of your DNS servers and if you need a basic firewall or not.
If something goes wrong, double-check that you correctly typed your username and password by looking at /etc/ppp/pap-secrets or /etc/ppp/chap-secrets and make sure you are using the right ethernet device. If your ethernet device doesn't exist, you will have to load the appropriate network modules. In that case you should continue with Manual Network Configuration as we explain how to load the appropriate network modules there. If everything worked, continue with Preparing the Disks. If you need PPTP support, you can use pptpclient which is provided by our LiveCDs. But first you need to make sure that your configuration is correct. Edit /etc/ppp/pap-secrets or /etc/ppp/chap-secrets so it contains the correct username/password combination:
Then adjust /etc/ppp/options.pptp if necessary:
When all that is done, just run pptp (along with the options you couldn't set in options.pptp) to connect the server:
Now continue with Preparing the Disks. 3.d. Manual Network Configuration Loading the Appropriate Network Modules When the Live CD boots, it tries to detect all your hardware devices and loads the appropriate kernel modules (drivers) to support your hardware. In the vast majority of cases, it does a very good job. However, in some cases, it may not auto-load the kernel modules you need. If net-setup or adsl-setup failed, then it is possible that your networkcard wasn't found immediately. This means you may have to load the appropriate kernel modules manually. To find out what kernel modules we provide for networking, use ls:
If you find a driver for your network card, use modprobe to load the kernel module:
To check if your network card is now detected, use ifconfig. A detected network card would result in something like this:
If however you receive the following error, the network card is not detected:
If you have multiple network cards in your system they are named eth0, eth1, etc. Make sure that the network card you want to use works well and remember to use the correct naming throughout this document. We will assume that the network card eth0 is used. Assuming that you now have a detected network card, you can retry net-setup or adsl-setup again (which should work now), but for the hardcore people amongst you we explain how to configure your network manually. Select one of the following sections based on your network setup:
DHCP (Dynamic Host Configuration Protocol) makes it possible to automatically receive networking information (IP address, netmask, broadcast address, gateway, nameservers etc.). This only works if you have a DHCP server in your network (or if your provider provides a DHCP service). To have a network interface receive this information automatically, use dhcpcd:
If this works (try pinging some internet server, like Google), then you are all set and ready to continue. Skip the rest of this section and continue with Preparing the Disks.
If you are using a wireless (802.11) card, you may need to configure your wireless settings before going any further. To see the current wireless settings on your card, you can use iwconfig. Running iwconfig might show something like:
For most users, there are only two settings that might be important to change, the ESSID (aka wireless network name) or the WEP key. If the ESSID and Access Point address listed are already that of your access point and you are not using WEP, then your wireless is working. If you need to change your ESSID, or add a WEP key, you can issue the following commands:
You can then confirm your wireless settings again by using iwconfig. Once you have wireless working, you can continue configuring the IP level networking options as described in the next section (Understanding Network Terminology) or use the net-setup tool as described previously. Understanding Network Terminology
If all above fails, you will have to configure your network manually. Have no fear, it is far from difficult. But we are going to explain a certain amount of networking to you as you will need it to be able to configure your network to your satisfaction. When you're done reading this, you will know what a gateway is, what a netmask serves for, how a broadcast address is formed and why you need nameservers. In a network, hosts are identified by their IP address (Internet Protocol address). Such an address is a combination of four numbers between 0 and 255. Well, at least that is how we perceive it. In reality, such an IP address consists of 32 bits (ones and zeros). Let's view an example:
Such an IP address is unique to a host as far as all accessible networks are concerned (i.e. all hosts that you are able to reach must have unique IP addresses). To be able to make a distinction between hosts inside a network, and hosts outside a network, the IP address is divided in two parts: the network part and the host part. The separation is written down with the netmask, a collection of ones followed by a collection of zeros. The part of the IP that can be mapped on the ones is the network-part, the other one is the host-part. As usual, the netmask can be written down as an IP-address.
In other words, 192.168.0.14 is still part of our example network, but 192.168.1.2 is not. The broadcast address is an IP-address with the same network-part as your network, but with only ones as host-part. Every host on your network listens to this IP address. It is truly meant for broadcasting packets.
To be able to surf on the internet, you must know which host shares the Internet connection. This host is called the gateway. Since it is a regular host, it has a regular IP address (for instance 192.168.0.1). We previously stated that every host has its own IP address. To be able to reach this host by a name (instead of an IP address) you need a service that translates a name (such as dev.gentoo.org) to an IP address (such as 64.5.62.82). Such a service is called a name service. To use such a service, you must define the necessary name servers in /etc/resolv.conf. In some cases, your gateway also serves as nameserver. Otherwise you will have to enter the nameservers provided by your ISP. To summarise, you will need the following information before continuing:
Setting up your network consists of three steps. First we assign ourselves an IP address using ifconfig. Then we set up routing to the gateway using route. Then we finish up by placing the nameserver IPs in /etc/resolv.conf. To assign an IP address, you will need your IP address, broadcast address and netmask. Then execute the following command, substituting ${IP_ADDR} with your IP address, ${BROADCAST} with your broadcast address and ${NETMASK} with your netmask:
Now set up routing using route. Substitute ${GATEWAY} with your gateway IP address:
Now open /etc/resolv.conf with your favorite editor (in our example, we use nano):
Now fill in your nameserver(s) using the following as a template. Make sure you substitute ${NAMESERVER1} and ${NAMESERVER2} with the appropriate nameserver addresses:
That's it. Now test your network by pinging some Internet server (like Google). If this works, congratulations then. You are now ready to install Gentoo. Continue with Preparing the Disks. 4. Preparing the Disks4.a. Introduction to Block Devices We'll take a good look at disk-oriented aspects of Gentoo Linux and Linux in general, including Linux filesystems, partitions and block devices. Then, once you're familiar with the ins and outs of disks and filesystems, you'll be guided through the process of setting up partitions and filesystems for your Gentoo Linux installation. To begin, we'll introduce block devices. The most famous block device is probably the one that represents the first IDE drive in a Linux system, namely /dev/hda. If your system uses SCSI or SATA drives, then your first hard drive would be /dev/sda. The block devices above represent an abstract interface to the disk. User programs can use these block devices to interact with your disk without worrying about whether your drives are IDE, SCSI or something else. The program can simply address the storage on the disk as a bunch of contiguous, randomly-accessible 512-byte blocks. Although it is theoretically possible to use a full disk to house your Linux system, this is almost never done in practice. Instead, full disk block devices are split up in smaller, more manageable block devices. On x86 systems, these are called partitions. Partitions are divided in three types: primary, extended and logical. A primary partition is a partition which has its information stored in the MBR (master boot record). As an MBR is very small (512 bytes) only four primary partitions can be defined (for instance, /dev/hda1 to /dev/hda4). An extended partition is a special primary partition (meaning the extended partition must be one of the four possible primary partitions) which contains more partitions. Such a partition didn't exist originally, but as four partitions were too few, it was brought to life to extend the formatting scheme without losing backward compatibility. A logical partition is a partition inside the extended partition. Their definitions aren't placed inside the MBR, but are declared inside the extended partition. The x86 LiveCDs provide support for EVMS and LVM2. EVMS and LVM2 increase the flexibility offered by your partitioning setup. During the installation instructions, we will focus on "regular" partitions, but it is still good to know EVMS and LVM2 are supported as well. 4.b. Designing a Partitioning Scheme If you are not interested in drawing up a partitioning scheme for your system, you can use the partitioning scheme we use throughout this book:
If you are interested in knowing how big a partition should be, or even how many partitions you need, read on. Otherwise continue now with partitioning your disk by reading Using fdisk to Partition your Disk. The number of partitions is highly dependent on your environment. For instance, if you have lots of users, you will most likely want to have your /home separate as it increases security and makes backups easier. If you are installing Gentoo to perform as a mailserver, your /var should be separate as all mails are stored inside /var. A good choice of filesystem will then maximise your performance. Gameservers will have a separate /opt as most gaming servers are installed there. The reason is similar for /home: security and backups. As you can see, it very much depends on what you want to achieve. Separate partitions or volumes have the following advantages:
However, multiple partitions have one big disadvantage: if not configured properly, you might result in having a system with lots of free space on one partition and none on another. There is also a 15-partition limit for SCSI and SATA. As an example partitioning, we show you one for a 20Gb disk, used as a demonstration laptop (containing webserver, mailserver, gnome, ...):
/usr is rather full (83% used) here, but once all software is installed, /usr doesn't tend to grow that much. For /var, people might think the assigned space is too much. However, Gentoo compiles all programs inside /var/tmp/portage, so you should have /var with at least 1G free if you don't want to compile big programs and at least 3G free if compiling KDE or OpenOffice.org is no big deal for you. 4.c. Using fdisk to Partition your Disk The following parts explain how to create the example partition layout described previously, namely:
Change your partition layout according to your own preference. Viewing the Current Partition Layout fdisk is a popular and powerful tool to split your disk into partitions. Fire up fdisk on your disk (in our example, we use /dev/hda):
Once in fdisk, you'll be greeted with a prompt that looks like this:
Type p to display your disk's current partition configuration:
This particular disk is configured to house seven Linux filesystems (each with a corresponding partition listed as "Linux") as well as a swap partition (listed as "Linux swap"). We will first remove all existing partitions from the disk. Type d to delete a partition. For instance, to delete an existing /dev/hda1:
The partition has been scheduled for deletion. It will no longer show up if you type p, but it will not be erased until your changes have been saved. If you made a mistake and want to abort without saving your changes, type q immediately and hit enter and your partition will not be deleted. Now, assuming that you do indeed want to wipe out all the partitions on your system, repeatedly type p to print out a partition listing and then type d and the number of the partition to delete it. Eventually, you'll end up with a partition table with nothing in it:
Now that the in-memory partition table is empty, we're ready to create the partitions. We will use a default partitioning scheme as discussed previously. Of course, don't follow these instructions to the letter if you don't want the same partitioning scheme! We first create a small boot partition. Type n to create a new partition, then p to select a primary partition, followed by 1 to select the first primary partition. When prompted for the first cylinder, hit enter. When prompted for the last cylinder, type +32M to create a partition 32 Mbyte in size:
Now, when you type p, you should see the following partition printout:
We need to make this partition bootable. Type a to toggle the bootable flag on a partition and select 1. If you press p again, you will notice that an * is placed in the "Boot" column. Let's now create the swap partition. To do this, type n to create a new partition, then p to tell fdisk that you want a primary partition. Then type 2 to create the second primary partition, /dev/hda2 in our case. When prompted for the first cylinder, hit enter. When prompted for the last cylinder, type +512M to create a partition 512MB in size. After you've done this, type t to set the partition type, 2 to select the partition you just created and then type in 82 to set the partition type to "Linux Swap". After completing these steps, typing p should display a partition table that looks similar to this:
Finally, let's create the root partition. To do this, type n to create a new partition, then p to tell fdisk that you want a primary partition. Then type 3 to create the third primary partition, /dev/hda3 in our case. When prompted for the first cylinder, hit enter. When prompted for the last cylinder, hit enter to create a partition that takes up the rest of the remaining space on your disk. After completing these steps, typing p should display a partition table that looks similar to this:
To save the partition layout and exit fdisk, type w.
Now that your partitions are created, you can now continue with Creating Filesystems. Now that your partitions are created, it is time to place a filesystem on them. If you don't care about what filesystem to choose and are happy with what we use as default in this handbook, continue with Applying a Filesystem to a Partition. Otherwise read on to learn about the available filesystems... The Linux kernel supports various filesystems. We'll explain ext2, ext3, ReiserFS, XFS and JFS as these are the most commonly used filesystems on Linux systems. ext2 is the tried and true Linux filesystem but doesn't have metadata journaling, which means that routine ext2 filesystem checks at startup time can be quite time-consuming. There is now quite a selection of newer-generation journaled filesystems that can be checked for consistency very quickly and are thus generally preferred over their non-journaled counterparts. Journaled filesystems prevent long delays when you boot your system and your filesystem happens to be in an inconsistent state. ext3 is the journaled version of the ext2 filesystem, providing metadata journaling for fast recovery in addition to other enhanced journaling modes like full data and ordered data journaling. ext3 is a very good and reliable filesystem. It has an additional hashed b-tree indexing option that enables high performance in almost all situations. In short, ext3 is an excellent filesystem. ReiserFS is a B*-tree based filesystem that has very good overall performance and greatly outperforms both ext2 and ext3 when dealing with small files (files less than 4k), often by a factor of 10x-15x. ReiserFS also scales extremely well and has metadata journaling. As of kernel 2.4.18+, ReiserFS is solid and usable as both general-purpose filesystem and for extreme cases such as the creation of large filesystems, the use of many small files, very large files and directories containing tens of thousands of files. XFS is a filesystem with metadata journaling which comes with a robust feature-set and is optimized for scalability. We only recommend using this filesystem on Linux systems with high-end SCSI and/or fibre channel storage and an uninterruptible power supply. Because XFS aggressively caches in-transit data in RAM, improperly designed programs (those that don't take proper precautions when writing files to disk and there are quite a few of them) can lose a good deal of data if the system goes down unexpectedly. JFS is IBM's high-performance journaling filesystem. It has recently become production-ready and there hasn't been a sufficient track record to comment positively nor negatively on its general stability at this point. Applying a Filesystem to a Partition To create a filesystem on a partition or volume, there are tools available for each possible filesystem:
For instance, to have the boot partition (/dev/hda1 in our example) in ext2 and the root partition (/dev/hda3 in our example) in ext3 (as in our example), you would use:
Now create the filesystems on your newly created partitions (or logical volumes). mkswap is the command that is used to initialize swap partitions:
To activate the swap partition, use swapon:
Create and activate the swap now. Now that your partitions are initialized and are housing a filesystem, it is time to mount those partitions. Use the mount command. Don't forget to create the necessary mount directories for every partition you created. As an example we mount the root and boot partition:
We will also have to mount the proc filesystem (a virtual interface with the kernel) on /proc. But first we will need to place our files on the partitions. Continue with Installing the Gentoo Installation Files. 5. Installing the Gentoo Installation Files5.a. Installing a Stage Tarball Before you continue you need to check your date/time and update it. A misconfigured clock may lead to strange results in the future! To verify the current date/time, run date:
If the date/time displayed is wrong, update it using the date MMDDhhmmYYYY syntax (Month, Day, hour, minute and Year). For instance, to set the date to April 25th, 16:21 in the year 2004:
The next step you need to perform is to install the stage tarball of your choice onto your system. You have the option of downloading the required tarball from the Internet or, if you are booted from one of the Gentoo Universal LiveCDs, copy it over from the CD itself. If you have a Universal CD and the stage you want to use is on the CD, downloading it from the Internet is just a waste of bandwidth as the stage files are the same. 5.b. Default: Using a Stage from the Internet Go to the Gentoo mountpoint at which you mounted your filesystems (most likely /mnt/gentoo):
Depending on your installation medium, you have a couple of tools available to download a stage. If you have links2 available, then you can immediately surf to the Gentoo mirrorlist and choose a mirror close to you. If you don't have links2 available you should have lynx at your disposal. In this case, substitute all occurrences of links2 in the rest of the instructions with lynx. Pick the releases/ directory, followed by your architecture (for instance x86/) and the Gentoo version (2004.2/) to finish up with the stages/ directory. There you should see all available stage files for your architecture (they might be stored within subdirectories named to the individual sub architectures). Select one and press D to download. When you're finished, press Q to quit the browser.
If you want to check the integrity of the downloaded stage tarball, use md5sum and compare the output with the MD5 checksum provided on the mirror. For instance, to check the validity of the x86 stage tarball:
Now unpack your downloaded stage onto your system. We use GNU's tar to proceed as it is the easiest method:
Make sure that you use the same options (-xvjpf). The x stands for Extract, the v for Verbose (okay, yes, this is optional), the j for Decompress with bzip2, the p for Preserve permissions and the f to denote that we want to extract a file, not standard input. Now that the stage is installed, continue with Installing Portage. 5.c. Alternative: Using a Stage from the LiveCD The stages on the CD reside in the /mnt/cdrom/stages directory. To see a listing of available stages, use ls:
If the system replies with an error, you may need to mount the CD-ROM first:
Now go into your Gentoo mountpoint (usually /mnt/gentoo):
We will now extract the stage tarball of your choice. We will do this with the GNU tar tool. Make sure you use the same options (-xvjpf)! In the next example, we extract the stage tarball stage3-<subarch>-2004.2.tar.bz2. Be sure to substitute the tarball filename with your stage.
Now that the stage is installed, continue with Installing Portage. If you don't have a working network connection, you have to install a Portage snapshot provided by one of our LiveCDs. This automatically assumes that you are installing from a stage3 tarball (as it is the only tarball supported for networkless installations). If you want to use prebuilt packages later on to speed up the installation, you must use a Portage snapshot from the LiveCD. Other users will download a fully updated Portage tree using emerge in the next chapter. Continue with the appropriate part:
Installing a Portage Snapshot and Source Code from LiveCD There is a Portage snapshot available on the Universal LiveCDs. Since you are reading this, we can safely assume you are using such a LiveCD. To install this snapshot, take a look inside /mnt/cdrom/snapshots/ to see what snapshot we have available:
Now extract the snapshot using the following construct. Again, make sure you use the correct options to tar. Also, the -C is with a capital C, not c. In the next example we use portage-20040710.tar.bz2 as the snapshot filename. Be sure to substitute with your snapshot.
You also need to copy over all source code from the CD:
Now that your Portage snapshot is installed, continue with Configuring the Compile Options. 5.e. Configuring the Compile Options To optimize Gentoo, you can set a couple of variables which impact Portage behaviour. All those variables can be set as environment variables (using export) but that isn't permanent. To keep your settings, Portage provides you with /etc/make.conf, a configuration file for Portage. It is this file we will edit now.
Fire up your favorite editor (in this guide we use nano) so we can alter the optimization variables we will discuss hereafter.
As you probably noticed, the make.conf.example file is structured in a generic way: commented lines start with "#", other lines define variables using the VARIABLE="content" syntax. The make.conf file uses the same syntax. Several of those variables are discussed next.
The CHOST variable defines what architecture gcc has to compile programs for. The possibilities are:
The CFLAGS and CXXFLAGS variables define the optimization flags for the gcc C and C++ compiler respectively. Although we define those generally here, you will only have maximum performance if you optimize these flags for each program separately. The reason for this is because every program is different. In make.conf you should define the optimization flags you think will make your system the most responsive generally. Don't place experimental settings in this variable; too much optimization can make programs behave bad (crash, or even worse, malfunction). We will not explain all possible optimization options. If you want to know them all, read the GNU Online Manual(s) or the gcc info page (info gcc -- only works on a working Linux system). The make.conf.example file itself also contains lots of examples and information; don't forget to read it too. A first setting is the -march= flag, which specifies the name of the target architecture. Possible options are described in the make.conf.example file (as comments). For instance, for the x86 Athlon XP architecture:
A second one is the -O flag (that is a capital O, not a zero), which specifies the gcc optimization class flag. Possible classes are s (for size-optimized), 0 (zero - for no optimizations), 1, 2 or 3 for more speed-optimization flags (every class has the same flags as the one before, plus some extras). For instance, for a class-2 optimization:
Another popular optimization flag is -pipe (use pipes rather than temporary files for communication between the various stages of compilation). Mind you that using -fomit-frame-pointer (which doesn't keep the frame pointer in a register for functions that don't need one) might have serious repercussions on the debugging of applications! When you define the CFLAGS and CXXFLAGS, you should combine several optimization flags, like in the following example:
With MAKEOPTS you define how many parallel compilations should occur when you install a package. A good choice is the number of CPUs in your system plus one, but this guideline isn't always perfect.
Update your /mnt/gentoo/etc/make.conf to your own preference and save (nano users would hit Ctrl-X). You are now ready to continue with Installing the Gentoo Base System. 6. Installing the Gentoo Base SystemIf you have booted from a Gentoo LiveCD, you are able to use mirrorselect to update /etc/make.conf so fast mirrors are used for both Portage and source code (of course in case you have a working network connection):
If for some reason mirrorselect fails, don't panic. This step is completely optional, the default values suffice. One thing still remains to be done before we enter the new environment and that is copying over the DNS information in /etc/resolv.conf. You need to do this to ensure that networking still works even after entering the new environment. /etc/resolv.conf contains the nameservers for your network.
Mount the /proc filesystem on /mnt/gentoo/proc to allow the installation to use the kernel-provided information even within the chrooted environment.
Now that all partitions are initialized and the base environment installed, it is time to enter our new installation environment by chrooting into it. This means that we change from the current installation environment (LiveCD or other installation medium) to your installation system (namely the initialized partitions). This chrooting is done in three steps. First we will change the root from / (on the installation medium) to /mnt/gentoo (on your partitions) using chroot. Then we will create a new environment using env-update, which essentially creates environment variables. Finally, we load those variables into memory using source.
Congratulations! You are now inside your own Gentoo Linux environment. Of course it is far from finished, which is why the installation still has some sections left :-) Optional: Updating the Portage tree If you haven't installed a Portage snapshot in the previous chapter, you must download a recent Portage tree from the Internet. emerge --sync does this for you. Other users should skip this and continue with Configuring the USE variable.
Portage uses the RSYNC protocol for updating the Portage tree. If the above command fails due to your firewall, use emerge-webrsync which downloads and installs a Portage snapshot for you using the regular HTTP protocol.
If you are warned that a new Portage version is available and that you should update Portage, you should ignore it. Portage will be updated for you later on during the installation. USE is one of the most powerful variables Gentoo provides to its users. Several programs can be compiled with or without optional support for certain items. For instance, some programs can be compiled with gtk-support, or with qt-support. Others can be compiled with or without SSL support. Some programs can even be compiled with framebuffer support (svgalib) instead of X11 support (X-server). Most distributions compile their packages with support for as much as possible, increasing the size of the programs and startup time, not to mention an enormous amount of dependencies. With Gentoo you can define what options a package should be compiled with. This is where USE comes into play. In the USE variable you define keywords which are mapped onto compile-options. For instance, ssl will compile ssl-support in the programs that support it. -X will remove X-server support (note the minus sign in front). gnome gtk -kde -qt will compile your programs with gnome (and gtk) support, and not with kde (and qt) support, making your system fully tweaked for GNOME. The default USE settings are placed in /etc/make.profile/make.defaults. What you place in /etc/make.conf is calculated against these defaults settings. If you add something to the USE setting, it is added to the default list. If you remove something from the USE setting (by placing a minus sign in front of it) it is removed from the default list (if it was in the default list at all). Never alter anything inside the /etc/make.profile directory; it gets overwritten when you update Portage! A full description on USE can be found in the second part of the Gentoo Handbook, USE flags. A full description on the available USE flags can be found on your system in /usr/portage/profiles/use.desc.
As an example we show a USE setting for a KDE-based system with DVD, ALSA and CD Recording support:
You will probably only use one or maybe two locales on your system. Up until now after compiling glibc a full set of all available locales will be created. As of now you can activate the userlocales USE flag and specify only the locales you will need in /etc/locales.build.
Now specify the locales you want to be able to use:
Optional: Using Distributed Compiling If you are interested in using a collection of systems to help in compiling your system you might want to take a look at our DistCC Guide. By using distcc you can use the processing power of several systems to aid you with the installation. 6.b. Differences between Stage1, Stage2 and Stage3 Now take a seat and think of your previous steps. We asked you to select a stage1, stage2 or stage3 and warned you that your choice is important for further installation steps. Well, this is the first place where your choice defines the subsequent steps.
6.c. Progressing from Stage1 to Stage2 So, you want to compile everything from scratch? Okay then :-) In this step, we will bootstrap your Gentoo system. This takes a long time, but the result is a system that has been optimized from the ground up for your specific machine and needs. Bootstrapping means building the GNU C Library, GNU Compiler Collection and several other key system programs. Before starting the bootstrap, we list a couple of options you might or might not want. If you do not want to read those, continue with Bootstrapping the System. Optional: Downloading the Sources First If you haven't copied over all source code before, then the bootstrap script will download all necessary files. It goes without saying that this only works if you have a working network connnection :-) If you want to download the source code first and later bootstrap the system (for instance because you don't want to have your internet connection open during the compilation) use the -f option of the bootstrap script, which will fetch (hence the letter f) all source code for you.
Okay then, take your keyboard and punch in the next commands to start the bootstrap. Then go amuse yourself with something else because this step takes quite some time to finish.
Now continue with the next step, Progressing from Stage2 to Stage3. 6.d. Progressing from Stage2 to Stage3 If you are reading this section, then you have a bootstrapped system (either because you bootstrapped it previously, or you are using a stage2). Then it is now time to build all system packages. All system packages? No, not really. In this step, you will build the system packages of which there are no alternatives to use. Some system packages have several alternatives (such as system loggers) and as Gentoo is all about choices, we don't want to force one upon you. Optional: Viewing what will be done If you want to know what packages will be installed, execute emerge --pretend system. This will list all packages that will be built. As this list is pretty big, you should also use a pager like less or more to go up and down the list.
Optional: Downloading the Sources If you want emerge to download the sources before you continue (for instance because you don't want the internet connection to be left open while you are building all packages) you can use the --fetchonly option of emerge which will fetch all sources for you.
To start building the system, execute emerge system. Then go do something to keep your mind busy, because this step takes a long time to complete.
You can for now safely ignore any warnings about updated configuration files (and running etc-update). When your Gentoo system is fully installed and booted, do read our documentation on Configuration File Protection. When the build process has completed, continue with Configuring the Kernel. 7. Configuring the KernelYou first need to select your timezone so that your system knows where it is located. Look for your timezone in /usr/share/zoneinfo, then make a symlink to /etc/localtime using ln:
The core around which all distributions are built is the Linux kernel. It is the layer between the user programs and your system hardware. Gentoo provides its users several possible kernel sources. A full listing with description is available at the Gentoo Kernel Guide. For x86-based systems we have, amongst other kernels, vanilla-sources (the default 2.4 kernel source as developed by the linux-kernel developers), gentoo-sources (2.4 kernel source patched with performance-enhancing features), gentoo-dev-sources (kernel v2.6 source patched with performance-enhancing features), development-sources (vanilla 2.6 kernel source), ... If you are performing a network-less install your kernel choices will be limited to those provided on the CD. For the 2004.2 release those are:
Choose your kernel source and install it using emerge.
When you take a look in /usr/src you should see a symlink called linux pointing to your kernel source. We will assume the kernel source installed is gentoo-sources-2.4.26-r6:
If this isn't the case (i.e. the symlink points to a different kernel source) change the symlink before you continue:
Now it is time to configure and compile your kernel source. You can use genkernel for this, which will build a generic kernel as used by the LiveCD. We explain the "manual" configuration first though, as it is the best way to optimize your environment. If you want to manually configure your kernel, continue now with Default: Manual Configuration. If you want to use genkernel you should read Alternative: Using genkernel instead. 7.c. Default: Manual Configuration Manually configuring a kernel is often seen as the most difficult procedure a Linux user ever has to perform. Nothing is less true -- after configuring a couple of kernels you don't even remember that it was difficult ;) However, one thing is true: you must know your system when you start configuring a kernel manually. Most information can be gathered by viewing the contents of /proc/pci (or by using lspci if available). You can also run lsmod to see what kernel modules the LiveCD uses (it might provide you with a nice hint on what to enable). Now go to your kernel source directory and execute make menuconfig. This will fire up an ncurses-based configuration menu.
You will be greeted with several configuration sections. We'll first list some options you must activate (otherwise Gentoo will not function, or not function properly without additional tweaks). First of all, activate the use of development and experimental code/drivers. You need this, otherwise some very important code/drivers won't show up:
Make sure that you compile your kernel with the correct processor family:
Now go to File Systems and select support for the filesystems you use. Don't compile them as modules, otherwise your Gentoo system will not be able to mount your partitions. Also select Virtual memory, /proc file system, /dev file system + Automatically mount at boot:
If your BIOS can't handle large harddrives and you jumpered the harddrive to report a limited size you have to enable the following option to gain access to your whole harddrive:
If you are using PPPoE to connect to the Internet or you are using a dial-up modem, you will need the following options in the kernel:
The two compression options won't harm but are not definitely needed, neither does the PPP over Ethernet option, that might only be used by rp-pppoe when configured to do kernel mode PPPoE. If you require it, don't forget to include support in the kernel for your ethernet card. If you have an Intel CPU that supports HyperThreading (tm), or you have a multi-CPU system, you should activate "Symmetric multi-processing support":
If you use USB Input Devices (like Keyboard our Mouse) don't forget to enable those as well:
Laptop-users who want PCMCIA support should not use the PCMCIA drivers if they choose to use a 2.4 kernel. More recent drivers are available through the pcmcia-cs package which will be installed later on. 2.6-kernel users however should use the PCMCIA drivers from the kernel. When you've finished configuring the kernel, continue with Compiling and Installing. Now that your kernel is configured, it is time to compile and install it. Exit the configuration and run make dep && make bzImage modules modules_install:
When the kernel has finished compiling, copy the kernel image to /boot. From here onwards we assume that the kernel you are installing is the 2.4.26 version of the gentoo-sources. Use whatever name you feel is appropriate for your choice and remember it as you will need it later on when you configure your bootloader.
It is also wise to copy over your kernel configuration file to /boot, just in case :)
Now continue with Installing Separate Kernel Modules. 7.d. Alternative: Using genkernel If you are reading this section, you have chosen to use our genkernel script to configure your kernel for you. Now that your kernel source tree is installed, it's now time to compile your kernel by using our genkernel script to automatically build a kernel for you. genkernel works by configuring a kernel nearly identically to the way our LiveCD kernel is configured. This means that when you use genkernel to build your kernel, your system will generally detect all your hardware at boot-time, just like our Live CD does. Because genkernel doesn't require any manual kernel configuration, it is an ideal solution for those users who may not be comfortable compiling their own kernels. Now, let's see how to use genkernel. First, emerge the genkernel ebuild:
Now, compile your kernel sources by running genkernel all. Be aware though, as genkernel compiles a kernel that supports almost all hardware, this compilation will take quite a while to finish! Note that, if your boot partition doesn't use ext2 or ext3 as filesystem you might need to manually configure your kernel using genkernel --menuconfig all and add support for your filesystem in the kernel (i.e. not as a module).
Once genkernel completes, a kernel, full set of modules and initial root disk (initrd) will be created. We will use the kernel and initrd when configuring a boot loader later in this document. Write down the names of the kernel and initrd as you will need it when writing the bootloader configuration file. The initrd will be started immediately after booting to perform hardware autodetection (just like on the Live CD) before your "real" system starts up.
Now, let's perform one more step to get our system to be more like the Live CD -- let's emerge hotplug. While the initrd autodetects hardware that is needed to boot your system, hotplug autodetects everything else. To emerge and enable hotplug, type the following:
7.e. Installing Separate Kernel Modules If appropriate, you should emerge ebuilds for any additional hardware that is on your system. Here is a list of kernel-related ebuilds that you could emerge:
Beware though, some of these ebuilds might deal with big dependencies. To verify what packages will be installed by emerging an ebuild, use emerge --pretend. For instance, for the emu10k1 package:
If you don't like the packages it wants to install, use emerge --pretend --verbose to see what USE-flags are checked when deciding the dependencies:
In the previous example you can see that one of emu10k1's dependencies (aumix) uses the gtk and gnome USE-flags, making gtk (which depends on xorg-x11) be compiled with it. If you don't want all this to be compiled, deselect all USE-flags, for instance:
When you're happy with the results, remove the --pretend to start installing emu10k1. You should list the modules you want automatically loaded in /etc/modules.autoload.d/kernel-2.4 (or kernel-2.6). You can add extra options to the modules too if you want. To view all available modules, run the following find command. Don't forget to substitute "<kernel version>" with the version of the kernel you just compiled:
For instance, to automatically load the 3c59x.o module, edit the kernel-2.4 or kernel-2.6 file and enter the module name in it.
Now run modules-update to commit your changes to the /etc/modules.conf file:
Continue the installation with Configuring your System. 8. Configuring your SystemUnder Linux, all partitions used by the system must be listed in /etc/fstab. This file contains the mountpoints of those partitions (where they are seen in the file system structure), how they should be mounted and with what special options (automatically or not, whether users can mount them or not, etc.) /etc/fstab uses a special syntax. Every line consists of six fields, separated by whitespace (space(s), tabs or a mixture). Each field has its own meaning:
The default /etc/fstab file provided by Gentoo is no valid fstab file, so start nano (or your favorite editor) to create your /etc/fstab:
Let us take a look at how we write down the options for the /boot partition. This is just an example, so if your architecture doesn't require a /boot partition (such as PPC), don't copy it verbatim. In our default x86 partitioning example /boot is the /dev/hda1 partition, with ext2 as filesystem. It needs to be checked during boot, so we would write down:
Some users don't want their /boot partition to be mounted automatically to improve their system's security. Those people should substitute defaults with noauto. This does mean that you need to manually mount this partition every time you want to use it. Now, to improve performance, most users would want to add the noatime option as mountoption, which results in a faster system since access times aren't registered (you don't need those generally anyway):
If we continue with this, we would end up with the following three lines (for /boot, / and the swap partition):
To finish up, you should add a rule for /proc, tmpfs (required) and for your CD-ROM drive (and of course, if you have other partitions or drives, for those too):
auto makes mount guess for the filesystem (recommended for removable media as they can be created with one of many filesystems) and user makes it possible for non-root users to mount the CD. Now use the above example to create your /etc/fstab. If you are a SPARC-user, you should add the following line to your /etc/fstab too:
If you need usbfs, add the following line to /etc/fstab:
Double-check your /etc/fstab, save and quit to continue. One of the choices the user has to make is name his/her PC. This seems to be quite easy, but lots of users are having difficulties finding the appropriate name for their Linux-pc. To speed things up, know that any name you choose can be changed afterwards. For all we care, you can just call your system tux and domain homenetwork. We use these values in the next examples. First we set the hostname:
Second we set the domainname:
If you have a NIS domain (if you don't know what that is, then you don't have one), you need to define that one too:
Now add the domainname script to the default runlevel:
Before you get that "Hey, we've had that already"-feeling, you should remember that the networking you set up in the beginning of the gentoo installation was just for the installation. Right now you are going to configure networking for your Gentoo system permanently. All networking information is gathered in /etc/conf.d/net. It uses a straightforward yet not intuitive syntax if you don't know how to set up networking manually. But don't fear, we'll explain everything :) First open /etc/conf.d/net with your favorite editor (nano is used in this example):
The first variable you'll find is iface_eth0. It uses the following syntax:
If you use DHCP (automatic IP retrieval), you should just set iface_eth0 to dhcp. If you use rp-pppoe (e.g. for ADSL), set it to up. If you need to set up your network manually and you're not familiar with all the above terms, please read the section on Understanding Network Terminology if you haven't done so already. So let us give three examples; the first one uses DHCP, the second one a static IP (192.168.0.2) with netmask 255.255.255.0, broadcast 192.168.0.255 and gateway 192.168.0.1 while the third one just activates the interface for rp-pppoe usage:
If you have several network interfaces, create extra iface_eth variables, like iface_eth1, iface_eth2 etc. The gateway variable shouldn't be reproduced as you can only set one gateway per computer. Now save the configuration and exit to continue. Automatically Start Networking at Boot To have your network interfaces activated at boot, you need to add them to the default runlevel. If you have PCMCIA interfaces you should skip this action as the PCMCIA interfaces are started by the PCMCIA init script.
If you have several network interfaces, you need to create the appropriate net.eth1, net.eth2 etc. initscripts for those. You can use ln to do this:
Writing Down Network Information You now need to inform Linux about your network. This is defined in /etc/hosts and helps in resolving hostnames to IP addresses for hosts that aren't resolved by your nameserver. For instance, if your internal network consists of three PCs called jenny (192.168.0.5), benny (192.168.0.6) and tux (192.168.0.7 - this system) you would open /etc/hosts and fill in the values:
If your system is the only system (or the nameservers handle all name resolution) a single line is sufficient. For instance, if you want to call your system tux.homenetwork:
Save and exit the editor to continue. If you don't have PCMCIA, you can now continue with System Information. PCMCIA-users should read the following topic on PCMCIA.
PCMCIA-users should first install the pcmcia-cs package. This also includes users who will be working with a 2.6 kernel (even though they won't be using the PCMCIA drivers from this package). The USE="-X" is necessary to avoid installing xorg-x11 at this moment:
When pcmcia-cs is installed, add pcmcia to the default runlevel:
First we set the root password by typing:
If you want root to be able to log on through the serial console, add tts/0 to /etc/securetty:
Gentoo uses /etc/rc.conf for general, system-wide configuration. Open up /etc/rc.conf and enjoy all the comments in that file :)
As you can see, this file is well commented to help you set up the necessary configuration variables. Take special care with the KEYMAP setting: if you select the wrong KEYMAP you will get weird results when typing on your keyboard.
PPC uses x86 keymaps on most systems. Users who want to be able to use ADB keymaps on boot have to enable ADB keycode sendings in their kernel and have to set a mac/ppc keymap in rc.conf. When you're finished configuring /etc/rc.conf, save and exit, then continue with Installing Necessary System Tools. 9. Installing Necessary System ToolsWhen we mentioned what stage3 was, we said that it contained all necessary system tools for which we cannot provide a choice to our users. We also said that we would install the other tools later on. Well, here we are :) The first tool you need to decide on has to provide logging facilities for your system. Unix and Linux have an excellent history of logging capabilities -- if you want you can log everything that happens on your system in logfiles. This happens through the system logger. Gentoo offers several system loggers to choose from. There are sysklogd, which is the traditional set of system logging daemons, syslog-ng, an advanced system logger, and metalog which is a highly-configurable system logger. Others might be available through Portage as well - our number of available packages increases on a daily basis. If you can't choose one, use metalog as it is very powerful yet comes with a great default configuration. To install the system logger of your choice, emerge it and have it added to the default runlevel using rc-update. The following example installs metalog. Of course substitute with your system logger:
Next is the cron daemon. Although it is optional and not required for your system, it is wise to install one. But what is a cron daemon? A cron daemon executes scheduled commands. It is very handy if you need to execute some command regularly (for instance daily, weekly or monthly). Gentoo offers three possible cron daemons: dcron, fcron and vixie-cron. Installing one of them is similar to installing a system logger. However, dcron and fcron require an extra configuration command, namely crontab /etc/crontab. If you don't know what to choose, use vixie-cron. We only provide vixie-cron for networkless installations. If you want another cron daemon you can wait and install it later on.
If you want to index your system's files so you are able to quickly locate them using the locate tool, you need to install sys-apps/slocate.
Depending on what file systems you are using, you need to install the necessary file system utilities (for checking the filesystem integrity, creating additional file systems etc.). The following table lists the tools you need to install if you use a certain file system:
If you don't require any additional networking-related tools (such as rp-pppoe or a dhcp client) continue with Configuring the Bootloader. Optional: Installing a DHCP Client If you require Gentoo to automatically obtain an IP address for your network interface(s), you need to install dhcpcd (or any other DHCP Client) on your system. If you don't do this now, you might not be able to connect to the internet after the installation!
Optional: Installing a PPPoE Client If you need rp-pppoe to connect to the net, you need to install it.
The USE="-X" will prohibit xorg-x11 to be installed as a dependency (rp-pppoe has graphical tools; if you want those enabled, you can recompile rp-pppoe later on or have xorg-x11 installed now -- which takes a long time to compile). Now continue with Configuring the Bootloader. 10. Configuring the BootloaderNow that your kernel is configured and compiled and the necessary system configuration files are filled in correctly, it is time to install a program that will fire up your kernel when you start the system. Such a program is called a bootloader. For x86, Gentoo Linux provides GRUB and LILO. But before we install one of these two bootloaders, we inform you how to configure framebuffer (assuming you want it of course). With framebuffer you can run the Linux command line with (limited) graphical features (such as using the nice bootsplash image Gentoo provides). If you have configured your kernel with framebuffer support (or you used genkernel's default kernel configuration), you have to add a vga- or video-statement to your bootloader configuration file if you require framebuffer. The former is for 2.4 kernels while you should use the latter for 2.6 kernels. The next table lists the available vga-values you can use. In the example configuration files we use 800x600 @ 16bpp for 2.4 kernels, thus 788. For the vga-statement:
For the video-statement, a simplified syntax is used. Most of the time it's sufficient to use video=vesafb. More information can be found in /usr/src/linux/Documentation/fb/vesafb.txt. Remember (or write down) your value; you will need it shortly. Now continue by installing GRUB or LILO. Understanding GRUB's terminology The most critical part of understanding GRUB is getting comfortable with how GRUB refers to hard drives and partitions. Your Linux partition /dev/hda1 is called (hd0,0) under GRUB. Notice the parenthesis around the hd0,0 - they are required. Hard drives count from zero rather than "a" and partitions start at zero rather than one. Be aware too that with the hd devices, only hard drives are counted, not atapi-ide devices such as cdrom players and burners. Also, the same construct is used with scsi drives. (Normally they get higher numbers than ide drives except when the bios is configured to boot from scsi devices.) Assuming you have a hard drive on /dev/hda, a cdrom player on /dev/hdb, a burner on /dev/hdc, a second hard drive on /dev/hdd and no SCSI hard drive, /dev/hdd7 gets translated to (hd1,6). It might sound tricky and tricky it is indeed, but as we will see, GRUB offers a tab completion mechanism that comes handy for those of you having a lot of hard drives and partitions and who are a little lost in the GRUB numbering scheme. Having gotten the feel for that, it is time to install GRUB. To install GRUB, let's first emerge it:
Although GRUB is now installed, we still need to write up a configuration file for it and place GRUB in our MBR so that GRUB automatically boots your newly created kernel. Create /boot/grub/grub.conf with nano (or, if applicable, another editor):
Now we are going to write up a grub.conf. Below you'll find two possible grub.conf for the partitioning example we use in this guide, with kernel image kernel-2.4.26-gentoo-r6. We've only extensively commented the first grub.conf. Make sure you use your kernel image filename and, if appropriate, your initrd image filename.
If you need to pass any additional options to the kernel, simply add them to the end of the kernel command. We're already passing one option (root=/dev/hda3 or real_root=/dev/hda3), but you can pass others as well. As an example we use the vga statement for framebuffer we discussed previously:
If you're using a 2.6.7 or higher kernel and you jumpered your harddrive because the BIOS can't handle large harddrives you'll need to append hdx=stroke. genkernel users should know that their kernels use the same boot options as is used for the LiveCD. For instance, if you have SCSI devices, you should add doscsi as kernel option. Now save the grub.conf file and exit. You still need to install GRUB in the MBR (Master Boot Record) so that GRUB is automatically executed when you boot your system. The GRUB developers recommend the use of grub-install. However, if for some reason grub-install fails to work correctly you still have the option to manually install GRUB. Continue with Default: Setting up GRUB using grub-install or Alternative: Setting up GRUB using manual instructions. Default: Setting up GRUB using grub-install To install GRUB you will need to issue the grub-install command. However, grub-install won't work off-the-shelf since we are inside a chrooted environment. We need to update /etc/mtab (the file with information about all mounted filesystems) first: luckily there is an easy way to accomplish this - just copy over /proc/mounts to /etc/mtab:
Now we can install GRUB using grub-install:
If you have more questions regarding GRUB, please consult the GRUB FAQ or the GRUB Manual. Continue with Rebooting the System. Alternative: Setting up GRUB using manual instructions To start configuring GRUB, you type in grub. You'll be presented with the grub> grub command-line prompt. Now, you need to type in the right commands to install the GRUB boot record onto your hard drive.
In the example configuration we want to install GRUB so that it reads its information from the boot-partition /dev/hda1, and installs the GRUB boot record on the hard drive's MBR (master boot record) so that the first thing we see when we turn on the computer is the GRUB prompt. Of course, if you haven't followed the example configuration during the installation, change the commands accordingly. The tab completion mechanism of GRUB can be used from within GRUB. For instance, if you type in "root (" followed by a TAB, you will be presented with a list of devices (such as hd0). If you type in "root (hd0," followed by a TAB, you will receive a list of available partitions to choose from (such as hd0,0). By using the tab completion, setting up GRUB should be not that hard. Now go on, configure GRUB, shall we? :-)
If you have more questions regarding GRUB, please consult the GRUB FAQ or the GRUB Manual. Continue with Rebooting the System. LILO, the LInuxLOader, is the tried and true workhorse of Linux bootloaders. However, it lacks some features that GRUB has (which is also the reason why GRUB is currently gaining popularity). The reason why LILO is still used is that, on some systems, GRUB doesn't work and LILO does. Of course, it is also used because some people know LILO and want to stick with it. Either way, Gentoo supports both, and apparently you have chosen to use LILO. Installing LILO is a breeze; just use emerge.
To configure LILO, you must create /etc/lilo.conf. Fire up your favorite editor (in this handbook we use nano for consistency) and create the file.
Some sections ago we have asked you to remember the kernel-image name you have created. In the next example lilo.conf we assume the imagename is kernel-2.4.26-gentoo-r6. We also use the example partitioning scheme in this example. There are two separate parts:
Make sure you use your kernel image filename and, if appropriate, your initrd image filename.
If you need to pass any additional options to the kernel, add an append statement to the section. As an example, we add the vga=788 statement to enable framebuffer:
If you're using a 2.6.7 or higher kernel and you jumpered your harddrive because the BIOS can't handle large harddrives you'll need to append hdx=stroke. genkernel users should know that their kernels use the same boot options as is used for the LiveCD. For instance, if you have SCSI devices, you should add doscsi as kernel option. Now save the file and exit. To finish up, you have to run /sbin/lilo so LILO can apply the /etc/lilo.conf to your system (i.e. install itself on the disk). Keep in mind that you'll also have to rerun /sbin/lilo every time you install a new kernel or make any changes to the menu.
You can now continue with Rebooting the System. Exit the chrooted environment and unmount all mounted partitions. Then type in that one magical command you have been waiting for: reboot.
Of course, don't forget to remove the bootable CD, otherwise the CD will be booted again instead of your new Gentoo system. Once rebooted in your Gentoo installation, finish up with Finalizing your Gentoo Installation. 11. Finalizing your Gentoo InstallationWorking as root on a Unix/Linux system is dangerous and should be avoided as much as possible. Therefore it is strongly recommended to add a user for day-to-day use. The groups the user is member of define what activities the user can perform. The following table lists a number of important groups you might wish to use:
For instance, to create a user called john who is member of the wheel, users and audio groups, log in as root first (only root can create users) and run useradd:
If a user ever needs to perform some task as root, they can use su - to temporarily receive root privileges. Another way is to use the sudo package which is, if correctly configured, very secure. 11.b. Optional: Install GRP Packages
Now that your system is booted, log on as the user you created (for instance, john) and use su - to gain root privileges:
Now we need to change the Portage configuration to look for the prebuilt binaries from the second CD (Gentoo Packages CD). First mount this CD:
Now configure Portage to use /mnt/cdrom for its prebuilt packages:
Now install the packages you want. The Packages CD contains several prebuilt binaries, for instance KDE:
Be sure to install the binaries now. When you do an emerge --sync to update Portage (as you will learn later), the prebuilt binaries might not match against the ebuilds in your updated Portage. You can try to circumvent this by using emerge --usepkgonly instead of emerge --usepkg. Congratulations, your system is now fully equiped! Continue with Where to go from here? to learn more about Gentoo. 12. Where to go from here?Congratulations! You now have a working Gentoo system. But where to go from here? What are your options now? What to explore first? Gentoo provides its users with lots of possibilities, and therefore lots of documented (and less documented) features. You should definitely take a look at the next part of the Gentoo Handbook entitled Working with Gentoo which explains how to keep your software up to date, how to install more software, what USE flags are, how the Gentoo Init system works, etc. If you are interested in optimizing your system for desktop-use, or you want to learn how to configure your system to be a full working desktop system, consult our extensive Gentoo Desktop Documentation Resources. For a full listing of all our available documentation check out our Documentation Resources page. You are of course always welcome on our Gentoo Forums or on one of our many Gentoo IRC channels. We also have several mailinglists open to all our users. Information on how to join is contained in that page. We'll shut up now and let you enjoy your installation :) B. Working with Gentoo1. A Portage IntroductionPortage is probably Gentoo's most notable innovation in software management. With its high flexibility and enormous amount of features it is frequently seen as the best software management tool available for Linux. Portage is completely written in Python and Bash and therefore fully visible to the users as both are scripting languages. Most users will work with Portage through the emerge tool. This chapter is not meant to duplicate the information available from the emerge man page. For a complete rundown of emerge's options, please consult the man page:
When we talk about packages, we often mean software titles that are available to the Gentoo users through the Portage tree. The Portage tree is a collection of ebuilds, files that contain all information Portage needs to maintain software (install, search, query, ...). These ebuilds reside in /usr/portage by default. Whenever you ask Portage to perform some action regarding software titles, it will use the ebuilds on your system as a base. It is therefore important that you regularly update the ebuilds on your system so Portage knows about new software, security updates, etc. The Portage tree is usually updated with rsync, a fast incremental file transfer utility. Updating is fairly simple as the emerge command provides a front-end for rsync:
If you are unable to rsync due to firewall restrictions you can still update your Portage tree by using our daily generated Portage tree snapshots. The emerge-webrsync tool automatically fetches and installs the latest snapshot on your system:
To search through the Portage tree after software titles, you can use emerge built-in search capabilities. By default, emerge search returns the names of packages whose title matches (either fully or partially) the given search term. For instance, to search for all packages who have "pdf" in their name:
If you want to search through the descriptions as well you can use the --searchdesc (or -S) switch:
When you take a look at the output, you'll notice that it gives you a lot of information. The fields are clearly labelled so we won't go further into their meanings:
Once you've found a software title to your liking, you can easily install it with emerge: just add the package name. For instance, to install gnumeric:
Since many applications depend on each other, any attempt to install a certain software package might result in the installation of several dependencies as well. Don't worry, Portage handles dependencies well. If you want to find out what Portage would install when you ask it to install a certain package, add the --pretend switch. For instance:
When you ask Portage to install a package, it will download the necessary source code from the internet (if necessary) and store it by default in /usr/portage/distfiles. After this it will unpack, compile and install the package. If you want Portage to only download the sources without installing them, add the --fetchonly option to the emerge command:
When you want to remove a software package from your system, use emerge unmerge. This will tell Portage to remove all files installed by that package from your system except the configuration files of that application if you have altered those after the installation. Leaving the configuration files allows you to continue working with the package if you ever decide to install it again. However, a big warning applies: Portage will not check if the package you want to remove is required by another package. It will however warn you when you want to remove an important package that breaks your system if you unmerge it.
When you remove a package from your system, the dependencies of that package that were installed automatically when you installed the software are left. To have Portage locate all dependencies that can now be removed, use emerge's depclean functionality. We will talk about this later on. To keep your system in perfect shape (and not to mention install the latest security updates) you need to update your system regularly. Since Portage only checks the ebuilds in your Portage tree you first have to update your Portage tree. When your Portage tree is updated, you can update your system with emerge --update world:
Portage will then search for newer version of the applications you have installed. However, it will only verify the versions for the applications you have explicitly installed - not the dependencies. If you want to update every single package on your system, add the --deep argument:
If you have altered any of your USE flags lately you might want to add --newuse as well. Portage will then verify if the change requires the installation of new packages or recompilation of existing ones:
Some packages in the Portage tree don't have any real content but are used to install a collection of packages. For instance, the kde package will install a complete KDE environment on your system by pulling in various KDE-related packages as dependencies. If you ever want to remove such a package from your system, running emerge unmerge on the package won't have much effect as the dependencies remain on the system. Portage has the functionality to remove orphaned dependencies as well, but since the availability of software is dynamically dependent you first need to update your entire system fully, including the new changes you applied when changing USE flags. After this you can run emerge depclean to remove the orphaned dependencies. When this is done, you need to rebuild the applications that were dynamically linked to the now-removed software titles but don't require them anymore. All this is handled with the following three commands:
revdep-rebuild is provided by the gentoolkit package; don't forget to emerge it first:
1.d. When Portage is Complaining... About SLOTs, Virtuals, Branches, Architectures and Profiles As we stated before, Portage is extremely powerful and supports many features that other software management tools lack. To understand this, we explain a few aspects of Portage without going in too much detail. With Portage different versions of a single package can coexist on a system. While other distributions tend to name their package to those versions (like freetype and freetype2) Portage uses a technology called SLOTs. An ebuild declares a certain SLOT for its version. Ebuilds with different SLOTs can coexist on the same system. For instance, the freetype package has ebuilds with SLOT="1" and SLOT="2". There are also packages that provide the same functionality but are implemented differently. For instance, metalogd, sysklogd and syslog-ng are all system loggers. Applications that rely on the availability of "a system logger" cannot depend on, for instance, metalogd, as the other system loggers are as good a choice as any. Portage allows for virtuals: each system logger provides virtual/syslog so that applications can depend on virtual/syslog. Software in the Portage tree can reside in different branches. By default your system only accepts packages that Gentoo deems stable. Most new software titles, when committed, are added to the testing branch, meaning more testing needs to be done before it is marked as stable. Although you will see the ebuilds for those software in the Portage tree, Portage will not update them before they are placed in the stable branch. Some software is only available for a few architectures. Or the software doesn't work on the other architectures, or it needs more testing, or the developer that committed the software to the Portage tree is unable to verify if the package works on different architectures. Each Gentoo installation adheres to a certain profile which contains, amongst other information, the list of packages that are required for a system to function normally.
Ebuilds contain specific fields that inform Portage about its dependencies. There are two possible dependencies: build dependencies, declared in DEPEND and run-time dependencies, declared in RDEPEND. When one of these dependencies explicitly marks a package or virtual as being not compatible, it triggers a blockage. To fix a blockage, you can choose to not install the package or unmerge the conflicting package first. In the given example, you can opt not to install libbonobo or to remove bonobo-activation first.
When you want to install a package that isn't available for your system, you will receive this masking error. You should try installing a different application that is available for your system or wait until the package is put available. There is always a reason why a package is masked:
The application you are trying to install depends on another package that is not available for your system. Please check bugzilla if the issue is known and if not, please report it. Unless you are mixing branches this should not occur and is therefore a bug.
The application you want to install has a name that corresponds with more than one package. You need to supply the category name as well. Portage will inform you of possible matches to choose from.
Two (or more) packages you want to install depend on each other and can therefore not be installed. This is most likely a bug in the Portage tree. Please resync after a while and try again. You can also check bugzilla if the issue is known and if not, report it.
Portage was unable to download the sources for the given application and will try to continue installing the other applications (if applicable). This failure can be due to a mirror that has not synchronised correctly or because the ebuild points to an incorrect location. The server where the sources reside can also be down for some reason. Retry after one hour to see if the issue still persists.
You have asked to remove a package that is part of your system's core packages. It is listed in your profile as required and should therefore not be removed from the system. 2. USE flagsWhen you are installing Gentoo (or any other distribution, or even operating system for that matter) you make choices depending on the environment you are working with. A setup for a server differs from a setup for a workstation. A gaming workstation differs from a 3D rendering workstation. This is not only true for choosing what packages you want to install, but also what features a certain package should support. If you don't need OpenGL, why would you bother installing OpenGL and build OpenGL support in most of your packages? If you don't want to use KDE, why would you bother compiling packages with KDE-support if those packages work flawlessly without? To help users in deciding what to install/activate and what not, we wanted the user to specify his/her environment in an easy way. This forces the user into deciding what they really want and eases the process for Portage, our package managment system, to make useful decisions. Enter the USE-flags. Such a flag is a keyword that embodies support and dependency-information for a certain concept. If you define a certain USE-flag, Portage will know that you want support for the chosen keyword. Of course this also alters the dependency information for a package. Let us take a look at a specific example: the kde keyword. If you do not have this keyword in your USE variable, all packages that have optional KDE support will be compiled without KDE support. All packages that have an optional KDE dependency will be installed without installing the KDE libraries (as dependency). If you have defined the kde keyword, then those packages will be compiled with KDE support, and the KDE libraries will be installed as dependency. By correctly defining the keywords you will receive a system tailored specifically to your needs. There are two types of USE-flags: global and local USE-flags.
A list of available global USE-flags can be found online or locally in /usr/portage/profiles/use.desc. A short (very incomplete) snippet:
A list of available local USE-flags can be found locally in /usr/portage/profiles/use.local.desc. In the hope you are convinced of the importance of USE-flags we will now inform you how to declare USE-flags. As previously mentioned, all USE-flags are declared inside the USE variable. To make it easy for users to search and pick USE-flags, we already provide a default USE setting. This setting is a collection of USE-flags we think are commonly used by the Gentoo users. This default setting is declared in the /etc/make.profile/make.defaults file. Let us take a look at this default setting:
As you can see, this variable already contains quite a lot of keywords. Do not alter the /etc/make.profile/make.defaults file to tailor the USE variable to your needs: changes in this file will be undone when you update Portage! To change this default setting, you need to add or remove keywords to the USE variable. This is done globally by defining the USE variable in /etc/make.conf. In this variable you add the extra USE-flags you require, or remove the USE-flags you don't want. This latter is done by prefixing the keyword with the minus-sign ("-"). For instance, to remove support for KDE and QT but add support for ldap, the following USE can be defined in /etc/make.conf:
Declaring USE flags for individual packages Sometimes you want to declare a certain USE flag for one (or a couple) of applications but not system-wide. To accomplish this, you will need to create the /etc/portage directory (if it doesn't exist yet) and edit /etc/portage/package.use. For instance, if you don't want berkdb support globally but you do want it for mysql, you would add:
You can of course also explicitly disable USE flags for a certain application. For instance, if you don't want java support in PHP:
Sometimes you want to set a certain USE-setting only once. Instead of editing /etc/make.conf twice (to do and undo the USE-changes) you can just declare the USE-variable as environment variable. Remember that, when you re-emerge or update this application (either explicitly or as part of a system update) your changes will be lost! As an example we will temporarily remove java from the USE-setting during the installation of mozilla.
Some packages don't only listen to USE-flags, but also provide USE-flags. When you install such a package, the USE-flag they provide is added to your USE setting. To view the list of packages that provide a USE-flag, check /etc/make.profile/use.defaults:
Of course there is a certain precedence on what setting has priority over the USE setting. You don't want to declare USE="-java" only to see that java is declared anyway. The precedence for the USE setting is, ordered by priority (first has lowest priority):
To view the final USE setting as seen by Portage, run emerge info. This will list all relevant variables (including the USE variable) with the content used by Portage.
Adapting your Entire System to New USE Flags If you have altered your USE flags and you wish to update your entire system to use the new USE flags, use emerge's --newuse option:
Next, run Portage's depclean to remove the conditional dependencies that were emerged on your "old" system but that have been obsoleted by the new USE flags.
When depclean has finished, run revdep-rebuild to rebuild the applications that are dynamically linked against shared objects provided by possibly removed packages. revdep-rebuild is part of the gentoolkit package; don't forget to emerge it first.
When all this is accomplished, your system is using the new USE flag settings. 2.c. Package specific USE-flags Let us take the example of mozilla: what USE-flags does it listen to? To find out, we use emerge with the --pretend and --verbose options:
emerge isn't the only tool for this job. In fact, we have a tool dedicated to package information called etcat which resides in the gentoolkit package. First, install gentoolkit:
Now run etcat with the uses argument to view the USE-flags of a certain package. For instance, for the gnumeric package:
3. Portage FeaturesPortage has several additional features that makes your Gentoo experience even better. Many of these features rely on certain software tools that improve performance, reliability, security, ... To enable or disable certain Portage features you need to edit /etc/make.conf's FEATURES variable. In several cases you will also need to install the additional tool on which the feature relies. Not all features that Portage supports are listed here. For a full overview, please consult the make.conf man page:
To find out what FEATURES are default set, run emerge info and search for the FEATURES variable or grep it out:
distcc is a program to distribute compilations across several, not necessarily identical, machines on a network. The distcc client sends all necessary information to the available distcc servers (running distccd) so they can compile pieces of source code for the client. The net result is a faster compilation time. You can find more information about distcc (and how to have it work with Gentoo) in our Gentoo Distcc Documentation. Distcc ships with a graphical monitor to monitor tasks that your computer is sending away for compilation. If you use Gnome then put 'gnome' in your USE variable. However, if you don't use Gnome and would still like to have the monitor then you should put 'gtk' in your USE variable.
Add distcc to the FEATURES variable inside /etc/make.conf. Next, edit the MAKEOPTS variable to your liking. A known guideline is to fill in "-jX" with X the number of CPUs that run distccd (including the current host) plus one, but you might have better results with other numbers. Now run distcc-config and enter the list of available distcc servers. For a simple example we assume that the available DistCC servers are 192.168.1.102 (the current host), 192.168.1.103 and 192.168.1.104 (two "remote" hosts):
Don't forget to run the distccd daemon as well:
ccache is a fast compiler cache. When you compile a program, it will cache intermediate results so that, whenever you recompile the same program, the compilation time is greatly reduced. In common compilations this can result in 5 to 10 times faster compilation times. If you are interested in the ins and outs of ccache, please visit the ccache homepage. To install ccache, run emerge ccache:
Open /etc/make.conf and add ccache to the FEATURES variable. Next, add a new variable called CCACHE_SIZE and set it to "2G":
To check if ccache functions, ask ccache to provide you with its statistics:
Using ccache for non-Portage C Compiling If you would like to use ccache for non-Portage compilations, add /usr/lib/ccache/bin to the beginning of your PATH variable (before /usr/bin). This can be accomplished by editing /etc/env.d/00basic:
Portage supports the installation of prebuilt packages. Even though Gentoo does not provide prebuilt packages by itself (except for the GRP snapshots) Portage can be made fully aware of prebuilt packages. To create a prebuilt package you can use quickpkg if the package is already installed on your system, or emerge with the --buildpkg or --buildpkgonly options. If you want Portage to create prebuilt packages of every single package you install, add buildpkg to the FEATURES variable. More extended support for creating prebuilt package sets can be obtained with catalyst. For more information on catalyst please read the Catalyst Reference Manual and Catalyst Howto. Although Gentoo doesn't provide one, you can create a central repository where you store prebuilt packages. If you want to use this repository, you need to make Portage aware of it by having the PORTAGE_BINHOST variable point to it. For instance, if the prebuilt packages are on ftp://buildhost/gentoo:
When you want to install a prebuilt package, add the --getbinpkg option to the emerge command alongside of the --usepkg option. The former tells emerge to download the prebuilt package from the previously defined server while the latter asks emerge to try to install the prebuilt package first before fetching the sources and compiling it. For instance, to install gnumeric with prebuilt packages:
More information about emerge's prebuilt package options can be found in the emerge man page:
4. InitscriptsWhen you boot your system, you will notice lots of text floating by. If you pay close attention, you will notice this text is the same every time you reboot your system. The sequence of all these actions is called the boot sequence and is (more or less) statically defined. First, your boot loader will load the kernel image you have defined in the boot loader configuration into memory after which it tells the CPU to run the kernel. When the kernel is loaded and run, it initializes all kernel-specific structures and tasks and starts the init process. This process then makes sure that all filesystems (defined in /etc/fstab) are mounted and ready to be used. Then it executes several scripts located in /etc/init.d, which will start the services you need in order to have a successfully booted system. Finally, when all scripts are executed, init activates the terminals (in most cases just the virtual consoles which are hidden beneath Alt-F1, Alt-F2, etc.) attaching a special process called agetty to it. This process will then make sure you are able to log on through these terminals by running login. Now init doesn't just execute the scripts in /etc/init.d randomly. Even more, it doesn't run all scripts in /etc/init.d, only the scripts it is told to execute. It decides which scripts to execute by looking into /etc/runlevels. First, init runs all scripts from /etc/init.d that have symbolic links inside /etc/runlevels/boot. Usually, it will start the scripts in alphabetical order, but some scripts have dependency information in them, telling the system that another script must be run before they can be started. When all /etc/runlevels/boot referenced scripts are executed, init continues with running the scripts that have a symbolic link to them in /etc/runlevels/default. Again, it will use the alphabetical order to decide what script to run first, unless a script has dependency information in it, in which case the order is changed to provide a valid start-up sequence. Of course init doesn't decide all that by itself. It needs a configuration file that specifies what actions need to be taken. This configuration file is /etc/inittab. If you remember the boot sequence we have just described, you will remember that init's first action is to mount all filesystems. This is defined in the following line from /etc/inittab:
This line tells init that it must run /sbin/rc sysinit to initialize the system. The /sbin/rc script takes care of the initialisation, so you might say that init doesn't do much -- it delegates the task of initialising the system to another process. Second, init executed all scripts that had symbolic links in /etc/runlevels/boot. This is defined in the following line:
Again the rc script performs the necessary tasks. Note that the option given to rc (boot) is the same as the subdirectory of /etc/runlevels that is used. Now init checks its configuration file to see what runlevel it should run. To decide this, it reads the following line from /etc/inittab:
In this case (which the majority of Gentoo users will use), the runlevel id is 3. Using this information, init checks what it must run to start runlevel 3:
The line that defines level 3, again, uses the rc script to start the services (now with argument default). Again note that the argument of rc is the same as the subdirectory from /etc/runlevels. When rc has finished, init decides what virtual consoles it should activate and what commands need to be run at each console:
You have seen that init uses a numbering scheme to decide what runlevel it should activate. A runlevel is a state in which your system is running and contains a collection of scripts (runlevel scripts or initscripts) that must be executed when you enter or leave a runlevel. In Gentoo, there are seven runlevels defined: three internal runlevels, and four user-defined runlevels. The internal runlevels are called sysinit, shutdown and reboot and do exactly what their names imply: initialize the system, powering off the system and rebooting the system. The user-defined runlevels are those with an accompanying /etc/runlevels subdirectory: boot, default, nonetwork and single. The boot runlevel starts all system-necessary services which all other runlevels use. The remaining three runlevels differ in what services they start: default is used for day-to-day operations, nonetwork is used in case no network connectivity is required, and single is used when you need to fix the system. The scripts that the rc process starts are called init scripts. Each script in /etc/init.d can be executed with the arguments start, stop, restart, pause, zap, status, ineed, iuse, needsme, usesme or broken. To start, stop or restart a service (and all depending services), start, stop and restart should be used:
If you want to stop a service, but not the services that depend on it, you can use the pause argument:
If you want to see what status a service has (started, stopped, paused, ...) you can use the status argument:
If the status information tells you that the service is running, but you know that it is not, then you can reset the status information to "stopped" with the zap argument:
To also ask what dependencies the service has, you can use iuse or ineed. With ineed you can see the services that are really necessary for the correct functioning of the service. iuse on the other hand shows the services that can be used by the service, but are not necessary for the correct functioning.
Similarly, you can ask what services require the service (needsme) or can use it (usesme):
Finally, you can ask what dependencies the service requires that are missing:
Gentoo's init system uses a dependency-tree to decide what service needs to be started first. As this is a tedious task that we wouldn't want our users to have to do manually, we have created tools that ease the administration of the runlevels and init scripts. With rc-update you can add and remove init scripts to a runlevel. The rc-update tool will then automatically ask the depscan.sh script to rebuild the dependency tree. You have already added init scripts to the "default" runlevel during the installation of Gentoo. At that time you might not have had a clue what the "default" is for, but now you should. The rc-update script requires a second argument that defines the action: add, del or show. To add or remove an init script, just give rc-update the add or del argument, followed by the init script and the runlevel. For instance:
The rc-update show command will show all the available init scripts and list at which runlevels they will execute:
Why the Need for Extra Configuration? Init scripts can be quite complex. It is therefore not really desirable to have the users edit the init script directly, as it would make it more error-prone. It is however important to be able to configure such a service. For instance, you might want to give more options to the service itself. A second reason to have this configuration outside the init script is to be able to update the init scripts without the fear that your configuration changes will be undone. Gentoo provides an easy way to configure such a service: every init script that can be configured has a file in /etc/conf.d. For instance, the apache2 initscript (called /etc/init.d/apache2) has a configuration file called /etc/conf.d/apache2, which can contain the options you want to give to the Apache 2 server when it is started:
Such a configuration file contains variables and variables alone (just like /etc/make.conf), making it very easy to configure services. It also allows us to provide more information about the variables (as comments). No, writing an init script is usually not necessary as Gentoo provides ready-to-use init scripts for all provided services. However, you might have installed a service without using Portage, in which case you will most likely have to create an init script. Do not use the init script provided by the service if it isn't explicitly written for Gentoo: Gentoo's init scripts are not compatible with the init scripts used by other distributions! The basic layout of an init script is shown below.
Any init script requires the start() function to be defined. All other sections are optional. There are two dependencies you can define: use and need. As we have mentioned before, the need dependency is more strict than the use dependency. Following this dependency type you enter the service you depend on, or the virtual dependency. A virtual dependency is a dependency that a service provides, but that is not provided solely by that service. Your init script can depend on a system logger, but there are many system loggers available (metalogd, syslog-ng, sysklogd, ...). As you cannot need every single one of them (no sensible system has all these system loggers installed and running) we made sure that all these services provide a virtual dependency. Let us take a look at the dependency information for the postfix service.
As you can see, the postfix service:
In some cases you might not require a service, but want your service to be started before (or after) another service if it is available on the system (note the conditional - this is no dependency anymore) and run in the same runlevel (note the conditional - only services in the same runlevel are involved). You can provide this information using the before or after settings. As an example we view the settings of the Portmap service:
You can also use the "*" glob to catch all services in the same runlevel, although this isn't advisable.
Next to the depend() functionality, you also need to define the start() function. This one contains all the commands necessary to initialize your service. It is advisable to use the ebegin and eend functions to inform the user about what is happening:
If you need more examples of the start() function, please read the source code of the available init scripts in your /etc/init.d directory. As for start-stop-daemon, there is an excellent man page available if you need more information:
Other functions you can define are: stop() and restart(). You are not obliged to define these functions! Our init system is intelligent enough to fill these functions by itself if you use start-stop-daemon. If you want your init script to support more options than the ones we have already encountered, you should add the option to the opts variable, and create a function with the same name as the option. For instance, to support an option called restartdelay:
Service Configuration Variables You don't have to do anything to support a configuration file in /etc/conf.d: if your init script is executed, the following files are automatically sourced (i.e. the variables are available to use):
Also, if your init script provides a virtual dependency (such as net), the file associated with that dependency (such as /etc/conf.d/net) will be sourced too. 4.e. Changing the Runlevel Behaviour Many laptop users know the situation: at home you need to start net.eth0 while you don't want to start net.eth0 while you're on the road (as there is no network available). With Gentoo you can alter the runlevel behaviour to your own will. For instance you can create a second "default" runlevel which you can boot that has other init scripts assigned to it. You can then select at boottime what default runlevel you want to use. First of all, create the runlevel directory for your second "default" runlevel. As an example we create the offline runlevel:
Add the necessary init scripts to the newly created runlevels. For instance, if you want to have an exact copy of your current default runlevel but without net.eth0:
Now edit your bootloader configuration and add a new entry for the offline runlevel. For instance, in /boot/grub/grub.conf:
Voila, you're all set now. If you boot your system and select the newly added entry at boot, the offline runlevel will be used instead of the default one. Using bootlevel is completely analogous to softlevel. The only difference here is that you define a second "boot" runlevel instead of a second "default" runlevel. 5. Environment VariablesAn environment variable is a named object that contains information used by one or more applications. Many users (and especially those new to Linux) find this a bit weird or unmanageable. However, this is a mistake: by using environment variables one can easily change a configuration setting for one or more applications. The following table lists a number of variables used by a Linux system and describes their use. Example values are presented after the table.
Below you will find an example definition of all these variables:
5.b. Defining Variables Globally To centralise the definitions of these variables, Gentoo introduced the /etc/env.d directory. Inside this directory you will find a number of files, such as 00basic, 05gcc, etc. which contain the variables needed by the application mentioned in their name. For instance, when you installed gcc, a file called 05gcc was created by the ebuild which contains the definitions of the following variables:
Other distributions tell you to change or add such environment variable definitions in /etc/profile or other locations. Gentoo on the other hand makes it easy for you (and for Portage) to maintain and manage the environment variables without having to pay attention to the numerous files that can contain environment variables. For instance, when gcc is updated, the /etc/env.d/05gcc file is updated too without requesting any user-interaction. This not only benefits Portage, but also you, as user. Occasionally you might be asked to set a certain environment variable system-wide. As an example we take the http_proxy variable. Instead of messing about with /etc/profile, you can now just create a file (/etc/env.d/99local) and enter your definition(s) in it:
By using the same file for all your variables, you have a quick overview on the variables you have defined yourself. Several files in /etc/env.d define the PATH variable. This is not a mistake: when you run env-update, it will append the several definitions before it updates the environment variables, thereby making it easy for packages (or users) to add their own environment variable settings without interfering with the already existing values. The env-update script will append the values in the alphabetical order of the /etc/env.d files. This is why many of the files in /etc/env.d begin with a number.
When you run env-update, the script will create all environment variables and place them in /etc/profile.env (which is used by /etc/profile). It will also extract the information from the LDPATH variable and use that to create /etc/ld.so.conf. After this, it will run ldconfig to recreate the /etc/ld.so.cache file used by the dynamical linker. If you want to notice the effect of env-update immediately after you run it, execute the following command to update your environment. Users who have installed Gentoo themselves will probably remember this from the installation instructions:
5.c. Defining Variables Locally You do not always want to define an environment variable globally. For instance, you might want to add /home/my_user/bin to the PATH variable but don't want all other users on your system to have that in their PATH too. If you want to define an environment variable locally, you should use ~/.bashrc or ~/.bash_profile:
When you relogin, your PATH variable will be updated. Sometimes even stricter definitions are requested. You might want to be able to use binaries from a temporary directory you created without using the path to the binaries themselves or editing ~/.bashrc for the short time you need it. In this case, you can just define the PATH variable in your current session by using the export command. As long as you don't log out, the PATH variable will be using the temporary settings.
C. Working with Portage1. Files and DirectoriesPortage comes with a default configuration stored in /etc/make.globals. When you take a look at it, you'll notice that all Portage configuration is handled through variables. What variables Portage listens to and what they mean are described later. Since many configuration directives differ between architectures, Portage also has a default configuration file inside your profile: /etc/make.profile/make.defaults. We'll explain more about profiles and the /etc/make.profile directory later on. If you're planning on changing a configuration variable, don't alter /etc/make.globals or /etc/make.profile/make.defaults. Instead use /etc/make.conf which has precedence over the previous files. You'll also find a /etc/make.conf.example. As the name implies, this is merely an example file - Portage does not read in this file. You can also define a Portage configuration variable as an environment variable, but we don't recommend this. We've already encountered the /etc/make.profile directory. Well, this isn't exactly a directory but a symbolic link to a profile, by default one inside /usr/portage/profiles although you can create your own profiles elsewhere and point to them. The profile this symlink points to is the profile to which your system adheres. A profile contains architecture-specific information for Portage, such as a list of packages that belong to the system corresponding with that profile, a list of packages that don't work (or are masked-out) for that profile, etc. When you need to override Portage's behaviour regarding the installation of software, you will end up editing files within /etc/portage. You are highly recommended to use files within /etc/portage and highly discouraged to override the behaviour through environment variables! Within /etc/portage you can create the following files:
More information about the /etc/portage directory and a full list of possible files you can create can be found in the Portage man page:
Changing Portage File & Directory Locations The previously mentioned configuration files cannot be stored elsewhere - Portage will always look for those configuration files at those exact locations. However, Portage uses many other locations for various purposes: build directory, source code storage, Portage tree location, ... All these purposes have well-known default locations but can be altered to your own taste through /etc/make.conf. The rest of this chapter explains what special-purpose locations Portage uses and how to alter their placement on your filesystem. This document isn't meant to be used as a reference though. If you need 100% coverage, please consult the Portage and make.conf man pages:
The Portage tree default location is /usr/portage. This is defined by the PORTDIR variable. When you store the Portage tree elsewhere (by altering this variable), don't forget to change the /etc/make.profile symbolic link accordingly. If you alter the PORTDIR variable, you might want to alter the following variables as well since they will not notice the PORTDIR change. This is due to how Portage handles variables: PKGDIR, DISTDIR, RPMDIR. Even though Portage doesn't use prebuilt binaries by default, it has extensive support for them. When you ask Portage to work with prebuilt packages, it will look for them in /usr/portage/packages. This location is defined by the PKGDIR variable. Application source code is stored in /usr/portage/distfiles by default. This location is defined by the DISTDIR variable. Even though Portage cannot use RPM files, it is able to generate them using the ebuild command (see The Ebuild Application). The default location where Portage stores RPM files is /usr/portage/rpm and is defined by the RPMDIR variable. Portage's temporary files are stored in /var/tmp by default. This is defined by the PORTAGE_TMPDIR variable. If you alter the PORTAGE_TMPDIR variable, you might want to alter the following variables as well since they will not notice the PORTAGE_TMPDIR change. This is due to how Portage handles variables: BUILD_PREFIX. Portage creates specific build directories for each package it emerges inside /var/tmp/portage. This location is defined by the BUILD_PREFIX variable. By default Portage installs all files on the current filesystem (/), but you can change this by setting the ROOT environment variable. This is useful when you want to create new build images. Portage can create per-ebuild logfiles, but only when the PORT_LOGDIR variable is set to a location that is writable by Portage (the portage user). By default this variable is unset. 2. Configuring through VariablesAs noted previously, Portage is configurable through many variables which you should define in /etc/make.conf. Please refer to the make.conf man page for more and complete information:
Configure and Compiler Options When Portage builds applications, it passes the contents of the following variables to the compiler and configure script:
The USE variable is also used during configure and compilations but has been explained in great detail in previous chapters. When Portage has merged a newer version of a certain software title, it will remove the obsoleted files of the older version from your system. Portage gives the user a 5 second delay before unmerging the older version. These 5 seconds are defined by the CLEAN_DELAY variable. 2.c. Configuration File Protection Portage overwrites files provided by newer versions of a software title if the files aren't stored in a protected location. These protected locations are defined by the CONFIG_PROTECT variable and are generally configuration file locations. The directory listing is space-delimited. A file that would be written in such a protected location is renamed and the user is warned about the presence of a newer version of the (presumable) configuration file. You can find out about the current CONFIG_PROTECT setting from the emerge info output:
More information about Portage's Configuration File Protection is available through emerge:
To 'unprotect' certain subdirectories of protected locations you can use the CONFIG_PROTECT_MASK variable. When the requested information or data is not available on your system, Portage will retrieve it from the Internet. The server locations for the various information and data channels are defined by the following variables:
A third setting involves the location of the rsync server which you use when you update your Portage tree:
The GENTOO_MIRRORS and SYNC variables can be set automatically through the mirrorselect application. You need to emerge mirrorselect first before you can use it. For more information, see mirrorselect's online help:
If your environment requires you to use a proxy server, you can use the HTTP_PROXY, FTP_PROXY and RSYNC_PROXY variables to declare a proxy server. When Portage needs to fetch source code, it uses wget by default. You can change this through the FETCHCOMMAND variable. Portage is able to resume partially downloaded source code. It uses wget by default, but this can be altered through the RESUMECOMMAND variable. Make sure that your FETCHCOMMAND and RESUMECOMMAND stores the source code in the correct location. Inside the variables you should use \${URI} and \${DISTDIR} to point to the source code location and distfiles location respectively. You can also define protocol-specific handlers with FETCHCOMMAND_HTTP, FETCHCOMMAND_FTP, RESUMECOMMAND_HTTP, RESUMECOMMAND_FTP, and so on. You cannot alter the rsync command used by Portage to update the Portage tree, but you can set some variables related to the rsync command:
You can change your default branch with the ACCEPT_KEYWORDS variable. It defaults to your architecture's stable branch. More information on Gentoo's branches can be found in the next chapter. You can activate certain Portage features through the FEATURES variable. The Portage Features have been discussed in previous chapters, such as Portage Features. With the PORTAGE_NICENESS variable you can augment or reduce the nice value Portage runs with. The PORTAGE_NICENESS value is added to the current nice value. For more information about nice values, see the nice man page:
The NOCOLOR, which defaults to "false", defines if Portage should disable the use of coloured output. 3. Mixing Software BranchesThe ACCEPT_KEYWORDS variable defines what software branch you use on your system. It defaults to the stable software branch for your architecture, for instance x86. We recommend that you only use the stable branch. However, if you don't care about stability this much and you want to help out Gentoo by submitting bugreports to http://bugs.gentoo.org, read on. If you want to use more recent software you can consider using the testing branch instead. To have Portage use the testing branch, add a ~ in front of your architecture. For instance, to select the testing branch for the x86 architecture, edit /etc/make.conf and set:
If you update your system now, you will find out that lots of packages will be updated. Mind you though: when you have updated your system to use the testing branch there is usually no easy way back to the stable, official branch (except for using backups of course). 3.b. Mixing Stable with Testing You can ask Portage to allow the testing branch for particular packages but use the stable branch for the rest of the system. To achieve this, add the package category and name you want to use the testing branch of in /etc/portage/package.keywords. For instance, to use the testing branch for gnumeric:
The same can be achieved when you add the correct keyword at the end of the line, for instance for the x86 architecture:
If you want to use a specific software version from the testing branch but you don't want Portage to use the testing branch for subsequent versions, you can add in the version in the package.keywords file. In this case you must use the = operator. You can also enter a version range using the <=, <, > or >= operators. In any case, if you add version information, you must use an operator. If you leave out version information, you cannot use an operator. In the following example we ask Portage to accept gnumeric-1.2.13:
When a package has been masked by the Gentoo developers and you still want to use it despite the reason mentioned in the package.mask file (situated in /usr/portage/profiles by default), add the exact same line in /etc/portage/package.unmask. For instance, if =net-mail/hotwayd-0.8 is masked, you can unmask it by adding the exact same line in the package.unmask file:
When you don't want Portage to take a certain package or a specific version of a package into account you can mask it yourself by adding an appropriate line to /etc/portage/package.mask. For instance, if you don't want Portage to install newer kernel sources than development-sources-2.6.8.1, you add the following line to package.mask:
4. Additional Portage Toolsetc-update is a tool that aids in merging the ._cfg0000_<name> files. It provides an interactive merging setup and can also auto-merge trivial changes. ._cfg0000_<name> files are generated by Portage when it wants to store a file in a directory protected by the CONFIG_PROTECT variable. Running etc-update is pretty straight-forward:
After merging the straightforward changes, you will be prompted with a list of protected files that have an update waiting. At the bottom you are greeted by the possible options:
If you enter -1, etc-update will exit without performing any changes. If you enter -3 or -5, all listed configuration files will be overwritten with the newer versions. It is therefore very important to first select the configuration files that should not be automatically updated. This is simply a matter of entering the number listed to the left of that configuration file. As an example, we select the configuration file /etc/pear.conf:
You can now see the differences between the two files. If you believe that the updated configuration file can be used without problems, enter 1. If you believe that the updated configuration file isn't necessary, or doesn't provide any new or useful information, enter 2. If you want to interactively update your current configuration file, enter 3. There is no point in further elaborating the interactive merging here. For completeness sake, we will list the possible commands you can use while you are interactively merging the two files. You are greeted with two lines (the original one, and the proposed new one) and a prompt at which you can enter one of the following commands:
When you have finished updating the important configuration files, you can now automatically update all the other configuration files. etc-update will exit if it doesn't find any more updateable configuration files. Using dispatch-conf you are able to merge updates to your configuration files while keeping track of all changes. dispatch-conf stores the differences between the configuration files as patches or by using the RCS revision system. Like etc-update, you can ask to keep the configuration file as-is, use the new configuration file, edit the current one or merge the changes interactively. However, dispatch-conf also has some nice additional features:
Make certain you edit /etc/dispatch-conf.conf first and create the directory referenced by the archive-dir variable. For more information, check out the dispatch-conf man page:
With quickpkg you can create archives of the packages that are already merged on your system. These archives can be used as prebuilt packages. Running quickpkg is straightforward: just add the names of the packages you want to archive. For instance, to archive curl, arts and procps:
The prebuilt packages will be stored in /usr/portage/packages/All. Symbolic links pointing to these packages are placed in /usr/portage/packages/<category>. 5. Diverting from the Official Tree5.a. Using a Portage Tree Subset You can selectively update certain categories/packages and ignore the other categories/packages. We achieve this by having rsync exclude categories/packages during the emerge --sync step. By default, rsync will check the contents of /etc/portage/rsync_excludes (if it exists) which contains the categories or packages that you don't want rsync to update. Note however that this may lead to dependency issues since new, allowed packages might depend on new but excluded packages. 5.b. Adding Unofficial Ebuilds Defining a Portage Overlay Directory You can ask Portage to use ebuilds that are not officially available through the Portage tree. Create a new directory (for instance /usr/local/portage) in which you store the 3rd-party ebuilds. Use the same directory structure as the official Portage tree! Then define PORTDIR_OVERLAY in /etc/make.conf and have it point to the previously defined directory. When you use Portage now, it will take those ebuilds into account as well without removing/overwriting those ebuilds the next time you run emerge --sync. 5.c. Non-Portage Maintained Software Using Portage with Self-Maintained Software In some cases you want to configure, install and maintain software yourself without having Portage automate the process for you, even though Portage can provide the software titles. Known cases are kernel sources and nvidia drivers. You can configure Portage so it knows that a certain package is manually installed on your system. This process is called injecting and supported by Portage through the /etc/portage/profile/package.provided file. For instance, if you want to inform Portage about development-sources-2.6.8.1 which you've installed manually, add the following line to /etc/portage/profile/package.provided:
6. The Ebuild ApplicationThe ebuild application is a lower level interface to the Portage system. Using this application you can execute specific actions against a given ebuild. For instance, you can perform the individual merging steps by yourself. Using ebuild is more for development purposes; more information about ebuild can therefore be found in the Developers Handbook. However, we will explain what ebuild instances are invoked by Portage during the merge process of a certain software title, and how to invoke the post-configuration steps some ebuilds allow you to perform. 6.b. Manually Installing Software Fetching the Sources & Checksumming Whenever you invoke ebuild against a given ebuild file, it will verify if the checksums of all involved files are equal to those given in the accompanying Manifest or files/digest-<name>-<version> file. This happens after the sources have been fetched. To fetch the sources using ebuild, run:
If the ebuild's md5sum does not match the one listed in the Manifest file, or one of the downloaded sources don't match those listed in the files/digest-<package> file, you will receive an error similar to this:
The subsequent line will mention the erroneous file. If you are certain that the sources you've fetched and the ebuild itself are valid, you can regenerate the Manifest and digest-<package> file using ebuild's digest functionality:
To unpack the sources in /var/tmp/portage (or any other directory location you have specified in /etc/make.conf), run ebuild's unpack functionality:
This will execute the ebuild's src_unpack() function (which defaults to plain extraction if no src_unpack() function is defined). It is also in this step that all necessary patches are applied. The next step in the merge process is to compile the sources. The ebuild's compile functionality takes care of this step by executing the src_compile() function in the ebuild. This also includes the configure steps if appropriate.
You are advised to edit the ebuild's src_compile() function if you want to change the compilation instructions. However, you can also trick Portage into believing that the ebuild application has finished the compile steps. Run all necessary commands yourself and create an empty file called .compiled in the working directory:
Installing the Files in a Temporary Location In the next step Portage will install all necessary files in a temporary location. This directory will then contain all files that are to be merged on the live filesystem. You can accomplish this by running ebuild's install functionality, which executes the ebuild's src_install() function:
Merging the Files onto the Live Filesystem The final step is to merge all files onto the live filesystem and register those in the Portage backend. ebuild calls this step "qmerge" and involves the following steps:
Run ebuild's qmerge functionality to accomplish these steps:
Cleaning the Temporary Directory Finally you can clean the temporary directory using ebuild's clean functionality:
6.c. Additional Ebuild Features Running all Merge-related Commands Using ebuild's merge functionality you can run the fetch, unpack, compile, install and qmerge commands in one go:
Performing Configuration Actions Some applications include instructions that configure the package further on your system. These instructions can be interactive and are therefore not automatically executed. To run these configuration steps, which are enlisted in the ebuild's (optional) config() function, use ebuild's config functionality:
You can instruct Portage to create a binary package of an ebuild or even an RPM file. Use ebuild's package or rpm functionality to create these archives. There are a few differences between those functionalities though:
The created RPM file however does not contain the ebuild's dependency information. Please consult the following man pages for more information about Portage, the ebuild application and the ebuild files:
You will also find more development-related information in the Developers Handbook. The contents of this document are licensed under the Creative Commons - Attribution / Share Alike license. |
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