The Gentoo Linux alternative installation method HOWTO

1.  About this document

If the standard boot-from-CD install method doesn't work for you (or you just don't like it), help is now here. This document serves to provide a repository of alternative Gentoo Linux installation techniques to those who need them. Or, if you prefer, it serves as a place to put your wacky installation methods. If you have an installation method that you yourself find useful, or you have devised an amusing way of installing Gentoo, please don't hesitate to write something up and post it on Bugzilla.

2.  Booting the Install CD with Smart BootManager

Download Smart BootManager available from http://btmgr.sourceforge.net/download.html. Linux source or binary format and windows .exe versions are available as well as many language packs. However, at this time, the preferred method would be to use the binary format, as the source will not compile with newer versions of NASM.

Either compile the package from source or just grab the binary. There are several options that can be utilized while creating your boot floppy, as seen below.

sbminst [-t theme] [-d drv] [-b backup_file] [-u backup_file]

   -t theme       select the theme to be used, in which the theme could be:
                    us = English theme       de = German theme
                    hu = Hungarian theme     zh = Chinese theme
                    ru = Russian theme       cz = Czech theme
                    es = Spanish theme       fr = French theme
                    pt = Portuguese theme


   -d drv         set the drive that you want to install Smart BootManager on;
                  for Linux:
                    /dev/fd0 is the first floppy driver,
                    /dev/hda is the first IDE harddisk driver.
                    /dev/sda is the first SCSI harddisk driver.
                  for DOS:
                    0   is the first floppy drive
                    128 is the first hard drive;

   -c             disable CD-ROM booting feature;

   -b backup_file backup the data that will be overwritten for
                  future uninstallation;

   -u backup_file uninstall Smart BootManager, should be used alone;

   -y             do not ask any question or warning.

# sbminst -t us  -d /dev/fd0

Now simply place the floppy in the floppy drive of the computer you'd like to boot the Install CD on, as well as placing the Install CD in the CD-ROM and boot the computer.

You'll be greeted with the Smart BootManager dialog. Select your CD-ROM and press ENTER to boot the Install CD. Once booted proceed with the standard installation instructions.

Further information on Smart BootManager may be found at http://btmgr.sourceforge.net/

3.  Installation from non-Gentoo LiveCDs

Introduction

It is possible to boot some other LiveCD besides the Gentoo-provided CDs. This will give you a functional environment to use while you're compiling and installing Gentoo. The instructions provided here should work in principle with just about any other LiveCD.

There are too many LiveCDs out there to list, but you might try Knoppix. It provides a full graphical desktop, with office applications, web browsers, and games to keep you busy. Knoppix is only available for x86 users, so depending on your needs you may need to find a different LiveCD.

Installation instructions

Boot from your LiveCD. Open a terminal and run su - so you can change your password. This lets you set the root password for the CD. You can now configure sshd for remote login, if you need to install Gentoo remotely. Next, you'll need to create the /mnt/gentoo mountpoint.

# mkdir /mnt/gentoo

At this point, you can pick up with the standard install documentation at part 4. However, when you are asked to mount the proc system, issue the following command instead:

# mount -o bind /proc /mnt/gentoo/proc

When you're ready to unpack the stage tarball in part 5, you will need to use a different tar command to ensure that proper group IDs are enforced on the unpacked stage:

# tar --numeric-owner -xvjpf stage3-*.tar.bz2

Once you're ready to chroot into your unpacked stage in part 6, you will need to use a different chroot command sequence. This ensures that your environment variables are properly setup.

(Some LiveCDs use a funny environment setup, hence the -i option for
cleaning it up to a reasonable state.)
# chroot /mnt/gentoo /bin/env -i TERM=$TERM /bin/bash
# env-update
# source /etc/profile
# export PS1="(chroot) $PS1"

Finally, know that some Portage FEATURES may not work in your LiveCD. Especially watch out for userpriv and usersandbox. If you find yourself getting errors, it might be wise to disable some or all of the optional FEATURES.

4.  Diskless install using PXE boot

Requirements

PXE (Preboot eXecution Environment) is a method for booting computers over a PXE-capable network interface (and using a PXE-supporting BIOS). It is also supported as a boot method from block devices (like CDs or USBs) in case the system does not support PXE boot from the network interface or BIOS. In such cases, a minimal boot environment mimics the PXE supporting network card (see also Etherboot/gPXE).

Server base setup

Create directories: The first thing to do is to create the directories where your diskless system will be stored. Create a directory called /diskless which houses a directory for each diskless client. For the rest of this howto we'll be working on the client 'eta'.

# mkdir /diskless
# mkdir /diskless/eta
# mkdir /diskless/eta/boot

DHCP and TFTP setup: The client will get boot informations using DHCP and download all the required files using TFTP.

For dhcpd, just run emerge dhcp (or any other DHCP server of your choice). Make sure that the correct interface is selected in /etc/conf.d/dhcpd, and configure it for your basic needs. Then, add the following on /etc/dhcp/dhcpd.conf.

option option-150 code 150 = text ;
ddns-update-style none ;
host eta {
hardware ethernet 00:00:00:00:00:00;
fixed-address ip.add.re.ss;
option option-150 "/eta/boot/grub.lst";
filename "/eta/boot/pxegrub";
}

Next you'll need to configure your interface in /etc/conf.d/net so that it doesn't get cleared at bootup. See /usr/share/doc/openrc-*/net.example.bz2 for more information.

(Replace eth0 with the correct interface)
config_eth0=( "noop" )

For TFTP, emerge net-ftp/tftp-hpa. In /etc/conf.d/in.tftpd, put the following :

INTFTPD_PATH="/diskless"
INTFTPD_USER="nobody"
INTFTPD_OPTS="-u ${INTFTPD_USER} -l -vvvvvv -p -c -s ${INTFTPD_PATH}"

Setup GRUB: To provide PXE booting I use GRUB with the netboot USE flag enabled. Once GRUB is compiled, copy the PXE image to the diskless client's boot directory. Then edit its grub.lst config file.

# echo "sys-boot/grub netboot" >> /etc/portage/package.use
# emerge -av grub
# cp /usr/lib/grub/pxegrub /diskless/eta/boot/pxegrub
# nano -w /diskless/eta/boot/grub.lst

default 0
timeout 30

title=Diskless Gentoo
root (nd)
kernel /eta/bzImage ip=dhcp root=/dev/nfs nfsroot=ip.add.re.ss:/diskless/eta

# For the nfsroot option, the IP address is the one of the server and
the directory is the one where your diskless client files are located (on the server).

Setup NFS: NFS is quite easy to configure. The only thing you have to do is to add a line on the /etc/exports config file:

# nano -w /etc/exports
# /etc/exports: NFS file systems being exported.  See exports(5).
/diskless/eta eta(rw,sync,no_root_squash)

Update your hosts: One important thing to do now is to modify your /etc/hosts file to fit your needs.

127.0.0.1 localhost

192.168.1.10 eta.example.com eta
192.168.1.20 sigma.example.com sigma

Creating the system on the server

You might want to reboot the server with a Gentoo Install CD, although you can very well continue immediately if you know how to proceed with the Gentoo Installation Instructions from an existing installation. Follow the standard install procedure as explained in the Gentoo Handbook BUT with the following differences: When you mount the file system, do the following (where sdaX is the partition where you created the /diskless directory). You do not need to mount any other partitions as all of the files will reside in the /diskless/eta directory.

# mount /dev/sdaX /mnt/gentoo

Stage tarballs and chroot: This example uses a stage3 tarball. Mount /proc to your diskless directory and chroot into it to continue with the install. Then follow the installation manual until kernel configuration.

# cd /mnt/gentoo/diskless/eta/
# tar -xvjpf  /mnt/cdrom/gentoo/stage3-*.tar.bz2
# mount -t proc /proc /mnt/gentoo/diskless/eta/proc
# cp /etc/resolv.conf /mnt/gentoo/diskless/eta/etc/resolv.conf
# chroot /mnt/gentoo/diskless/eta/ /bin/bash
# env-update
# source /etc/profile

Kernel configuration: When you do the make menuconfig of your kernel configuration, don't forget to enable the following options with the others recommended into the install howto.

- Your network card device support
(In the kernel, *not* as a module!)

- Under "Networking options" :

[*] TCP/IP networking
[*] IP: kernel level autoconfiguration
[*] IP: DHCP support
[*] IP: BOOTP support


- Under "File systems --> Network File Systems" :

<*> NFS file system support
[*] Provide NFSv3 client support
[*] Root file system on NFS

Save the kernel in your chrooted / (not in /boot) according to the pxegrub setting defined earlier. Next configure your diskless client's /etc/fstab.

# nano -w /etc/fstab
/dev/cdroms/cdrom0 /mnt/cdrom iso9660 noauto,ro 0 0

You also need to prevent the client to run a filesystem check:

# touch /fastboot
# echo "touch /fastboot" >> /etc/conf.d/local.start

Install nfs-utils since your client will heavily depend on it:

# emerge nfs-utils

Bootloader. Don't install another bootloader because we already have one - pxegrub. Simply finish the install and restart the server. Start the services you'll need to boot the new client: DHCP, TFTPD, and NFS.

# /etc/init.d/dhcp start
# /etc/init.d/in.tftpd start
# /etc/init.d/nfs start

Booting the new client

For the new client to boot properly, you'll need to configure the bios and the network card to use PXE as the first boot method - before CD-ROM or floppy. For help with this consult your hardware manuals or manufacturers website. The network card should get an IP address using DHCP and download the GRUB PXE image using TFTP. Then, you should see a nice black and white GRUB bootmenu where you will select the kernel to boot and press Enter. If everything is ok the kernel should boot, mount the root filesystem using NFS and provide you with a login prompt. Enjoy.

5.  Installing Gentoo from an existing Linux distribution

Requirements

In order to install Gentoo from your existing Linux distribution you need to have chroot command installed, and have a copy of the Gentoo installation tarball or ISO you want to install. A network connection would be preferable if you want more than what's supplied in your tarball. (by the way, a tarball is just a file ending in .tbz or .tar.gz). The author used RedHat Linux 7.3 as the "host" operating system, but it is not very important. Let's get started!

Overview

We will first allocate a partition to Gentoo by resizing our existing Linux partition, mount the partition, untar the tarball to the partition that is mounted, chroot inside the pseudo-system and start building. Once the bootstrap process is done, we will do some final configuration on the system so as to make sure it boots, then we are ready to reboot and use Gentoo.

How should we make space for Gentoo?

The root partition is the filesystem mounted under /. A quick run of mount on my system shows what I am talking about. We well also use df (disk free) to see how much space I have left and how I will be resizing. Note that it is not mandatory to resize your root partition! You could be resizing anything else supported by our resizer, but let's talk about that later.

# mount
/dev/sdb2 on / type ext3 (rw)
none on /proc type proc (rw)
none on /dev/pts type devpts (rw,gid=5,mode=620)
none on /dev/shm type tmpfs (rw,nodev,nosuid,noexec)
# df -h 
Filesystem           Size Used Avail Use% Mounted on
/dev/sdb2            4.0G 1.9G  2.4G  82% /
none                  38M    0   38M   0% /dev/shm

As we can see, the partition mounted as / named /dev/sdb2 has 2.4 gigabytes free. In my case, I think I will resize it as to leave 400Megs free of space, therefore allocating 2 gigabytes for Gentoo. Not bad, I could have quite some stuff installed. However, I think that even one gigabyte is enough for most users. So let's partition this thing!

Building parted to resize partition

Parted is an utility supplied by the GNU foundation, an old and respectable huge project whose software you are using in this very moment. There is one tool, however, that is extremely useful for us at the moment. It's called parted, partition editor and we can get it from http://www.gnu.org/software/parted/

Look up on that page the type of filesystem you want to resize and see if parted can do it. If not, you're out of luck, you will have to destroy some partition to make space for Gentoo, and reinstall back. Go ahead by downloading the software, install it. Here we have a problem. We want to resize our Linux root partition, therefore we must boot from a floppy disk a minimal linux system and use previously-compiled parted copied to a diskette in order to resize /. However, if you can unmount the partition while still in Linux you are lucky, you don't need to do what follows. Just compile parted and run it on an unmounted partition you chose to resize. Here's how I did it for my system.

Get the mininux boot/root disk (a 2.4-powered mini Linux distribution on a floppy - free of charge) from http://mininux.free.fr/uk/, create a floppy as suggested in the Documentation that accompanies the software package and insert a new floppy in the drive for the next step.

# mkfs.minix /dev/fd0
480 inodes
1440 blocks
Firstdatazone=19 (19)
Zonesize=1024
Maxsize=268966912

We will now proceed with the build of parted. If it's not already downloaded and untarred, do so now and cd into the corresponding directory. Now run the following set of commands to build the utility and copy it to your floppy disk.

#  mkdir /floppy; mount -t minix /dev/fd0 /floppy &&
export CFLAGS="-O3 -pipe -fomit-frame-pointer -static" && ./configure
&& make && cp parted/parted /floppy && umount /floppy 

Congratulations, you are ready to reboot and resize your partition. Do this only after taking a quick look at the parted documentation on the GNU website. The resize should take under 30 minutes for the largest hard-drives, be patient. Reboot your system with the mininux boot disk (just pop it inside), and once you are logged in, switch the disk in the drive with your utility disk we have created above and type mount /dev/fd0 /floppy to have parted under /floppy. There you go. Run parted and you will be able to resize your partition. Once this lenghty process done, we are ready to have the real fun, by installing Gentoo. Reboot back into your old Linux system for now. The drive you wish to operate on is the drive containing the partition we want to resize. For example, if we want to resize /dev/sda3, the drive is /dev/sda.

# mount /dev/fd0 /floppy 
# cd /floppy; ./parted [drive you wish to operate on]
(parted)  print 
Disk geometry for /dev/sdb: 0.000-9787.148 megabytes
Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.031   2953.125  primary   ntfs
3       2953.125   3133.265  primary   linux-swap
2       3133.266   5633.085  primary   ext3
4       5633.086   9787.148  extended
5       5633.117   6633.210  logical
6       6633.242   9787.148  logical   ext3
(parted)  help resize 
  resize MINOR START END        resize filesystem on partition MINOR

        MINOR is the partition number used by Linux.  On msdos disk labels, the
        primary partitions number from 1-4, and logical partitions are 5
        onwards.
        START and END are in megabytes
(parted)  resize 2 3133.266 4000.000 

Once you have resized, boot back into your old linux as described. Then go to The Gentoo Handbook: Preparing the Disks and follow the instructions. When chrooting, use the following command to flush your environment:

# env -i HOME=$HOME TERM=$TERM chroot /mnt/gentoo /bin/bash
# /usr/sbin/env-update
# source /etc/profile

Enjoy!

The contents of this document, unless otherwise expressly stated, are licensed under the CC-BY-SA-2.5 license. The Gentoo Name and Logo Usage Guidelines apply.