Gentoo Linux Frequently Asked Questions
Please note that many of these questions are answered within the official
Gentoo documents and guides. This is simply a list of common questions. Please
read the documentation and/or man pages to gain a greater understanding of how
Gentoo and GNU/Linux works, and for answers to questions which may not be
How is Gentoo pronounced, and what does it mean?
Gentoo is pronounced "gen-too" (the "g" in "Gentoo" is a soft "g", as in
"gentle"). The scientific name of the Gentoo penguin is
Pygoscelis papua. The name Gentoo has been given to the penguin
by the inhabitants of the Falkland Islands.
What makes Gentoo different?
Gentoo uses a BSD ports-like system called Portage. Portage is a package management system
that allows great flexibility while installing and maintaining software on a
Gentoo system. It provides compile-time option support (through USE flags),
conditional dependencies, pre-package installation summary, safe installation
(through sandboxing) and uninstallation of software, system profiles, configuration
file protection amongst several other features.
With Gentoo you can build your entire system from source, using your choice of
optimizations. You have complete control over what packages are or aren't
installed. Gentoo provides you with numerous choices, so you can install Gentoo
to your own preferences, which is why Gentoo is called a meta-distribution.
Gentoo is actively developed. The entire distribution uses a rapid pace
development style: patches to the packages are quickly integrated in the
mainline tree, documentation is updated on daily basis, Portage features are
added frequently, and official releases occur twice per year.
Things are really unstable and I'm using -O9 -ffast-math
-fomit-frame-pointer optimizations. What gives?
Don't bother using anything higher than -O3 since it isn't supported by
current versions of gcc. Very aggressive optimizations sometimes cause the
compiler to streamline the assembly code to the point where it doesn't quite
do the same thing anymore.
Please try to compile with CFLAGS -O2 -march=<your_arch> before
reporting a bug.
How do I change the root (or any other user's) password?
You can use passwd to change the password for the user you are logged
into. As root, you can change any user password by issuing the command
passwd username For extra options and setting, please man passwd.
How do I add a normal user?
The command useradd username will add a user called "username". However,
this method does not give the user many of the rights you might want to grant
him, so the following command is preferred:
Code Listing 3.1: Using useradd
# useradd -m -G users,audio,wheel username
This will add a user named "username". The option audio adds them to the
audio group and allows the user to access sound devices. The option
wheel adds the user to the wheel group, which allows the user to
execute the command su, which in turn allows them to gain the
privileges of the root user.
Why can't a user su to root?
For security reasons, users may only su to root if they belong to the
wheel group. To add a username to the wheel group, issue the following command
Code Listing 3.2: Adding a user to the wheel group
# gpasswd -a username wheel
Can I upgrade Gentoo from one release to another without reinstalling?
In fact, there is no difference between the various releases after they have
been installed. Gentoo 1.4 and later are glibc-2.3.x (or higher) based.
As such, running emerge --sync && emerge -uDN world will bring your
entire system up to speed with the "latest Gentoo". The differences between
individual releases lie in the installation medium and pre-compiled packages.
See the Gentoo Upgrading Guide
for more information about profiles and their role in upgrading.
Also note that the emerge -uDN world command updates the packages you
have installed as well as its dependencies, but not the build-time dependencies
(packages needed during builds but not when the software is installed). To
update those as well, add the --with-bdeps=y option.
My kernel doesn't boot, what should I do now?
You don't need to redo every step of the installation, but investigating the
kernel and all associated steps is necessary. Suppose you have installed Gentoo
on /dev/sda1 (/boot) and /dev/sda3 (/) with
/dev/sda2 being the swap space:
Code Listing 3.3: Reconfiguring the kernel
# mount /dev/sda3 /mnt/gentoo
# mount /dev/sda1 /mnt/gentoo/boot
# swapon /dev/sda2
# mount -t proc none /mnt/gentoo/proc
# chroot /mnt/gentoo /bin/bash
# env-update && source /etc/profile
# cd /usr/src/linux
# make menuconfig
# make && make modules_install
# cp arch/i386/boot/bzImage /boot/<kernel_name>
# umount /mnt/gentoo/proc /mnt/gentoo/boot /mnt/gentoo
If, on the other hand, the problem lies with your bootloader configuration,
follow the same steps, but instead of configuring/compiling your kernel, you
should reconfigure your bootloader (recompilation isn't necessary).
My proxy requires authentication, what do I have to do?
To have Portage automatically use this scheme, define it in
Code Listing 3.4: /etc/portage/make.conf
How do I burn an ISO file?
You need to burn the file in raw mode. This means that you should not
just place the file on the CD, but interpret the file as an entire CD.
There are lots of CD burning tools available; covering them all would be a
Sisyphean problem. However, describing a few popular tools never hurts:
With EasyCD Creator you select File, Record CD
from CD image. Then you change the Files of type to ISO image
file. Then locate the ISO file and click Open. When you click on
Start recording the ISO image will be burned correctly onto the CD-R.
With Nero Burning ROM, cancel the wizard which automatically pops up and
select Burn Image from the File menu. Select the image you
want to burn and click Open. Now hit the Burn button and watch
your brand new CD being burnt.
With cdrecord, you simply type cdrecord dev=/dev/sdc (replace
/dev/sdc with your CD-RW drive's device path) followed
by the path to the ISO file :)
With K3B, select Tools > CD > Burn CD Image.
Then you can locate your ISO file within the 'Image to Burn' area. Finally
With Mac OS X Panther, launch Disk Utility from
Applications/Utilities, select Open from the
Images menu, select the mounted disk image in the main window and
select Burn in the Images menu.
With Mac OS X Jaguar, launch Disk Copy from
Applications/Utilities, select Burn Image from the
File menu, select the ISO and click the Burn button.
What CD/stage should I use for my CPU?
First you need to find out what CPU you use. Suppose it's a Pentium-M. Then you
need to find out what CPU it is, instruction-wise, compatible with. You may
need to consult the CPU's vendor website for this, although Google is at least as efficient :-).
If you are uncertain, take a "lower" CD/stage file, for instance a i686 or even
generic x86 (or the equivalent in your arch). This will ensure that your system
will work, but may not be as fast as further optimizations.
Please note that many more options exist than those for which Gentoo builds
binary stages. Please see the gcc
guide for setting -march.
I can't get online after rebooting. What is wrong?
First you need to check if your network card is discovered properly by the
kernel. Run ifconfig -a and look for eth0 or wlan0 (in case of
certain wireless network cards). You might need to load specific kernel modules
for the kernel to properly detect the network card. If that is the case, make
sure that these kernel modules are listed in
If you have forgotten to include support for your network card in your kernel,
you will need to reconfigure your kernel.
If your network card is found by your kernel, but you have set your networking
configuration to use DHCP, you might have forgotten to
emerge dhcpcd. You will need to reboot with your installation CD to
Information on how to rescue your system using the installation CD is available as well.
I want to boot Windows from grub or lilo but it shows only black screen. What
should I do?
This is a known problem. Windows refuses to boot when it isn't installed on the
first hard drive and shows a black/blank screen. To handle this, you will have
to "fool" Windows into believing that it is installed on the first hard drive
with a little tweak in your boot loader configuration. Please note that in the
below example, Gentoo is installed on sda (first disk) and Windows
on sdb (second one). Adjust your config as needed.
Code Listing 3.5: Example dual boot entry for Windows in grub.conf
title Windows XP
map (hd1) (hd0)
map (hd0) (hd1)
Code Listing 3.6: Example dual boot entry for Windows in lilo.conf
map-drive = 0x80
to = 0x81
map-drive = 0x81
to = 0x80
This will make Windows believe it is installed on the first hard drive and boot
without problems. More information can be found in the GRUB documentation and in man
lilo.conf, depending on the boot loader you're using.
How do I Install Gentoo Using a Stage1 or Stage2 Tarball?
The Gentoo Handbook only describes a Gentoo installation using a stage3 tarball.
However, Gentoo still provides stage1 and stage2 tarballs. This is for
development purposes (the Release Engineering team starts from a stage1 tarball
to obtain a stage3) but shouldn't be used by users: a stage3 tarball can very
well be used to bootstrap the system. You do need a working Internet connection.
Bootstrapping means building the toolchain (the C library and compiler) for
your system after which you install all core system packages. To bootstrap the
system, perform a stage3 installation. Before you start the chapter on
Configuring the Kernel, modify the bootstrap.sh script to
suit your needs and then run it:
Code Listing 3.7: Bootstrapping the system
# cd /usr/portage/scripts
# vi bootstrap.sh
Next, rebuild all core system packages with the newly built toolchain. We need
to rebuild them since the stage3 tarball already offers them:
Code Listing 3.8: Rebuilding the core system packages
# emerge -e system
Now you can continue with Configuring the Kernel. You can not use the
prebuilt GRP packages anymore though.
In what form are the packages stored?
Packages aren't "stored" per se. Instead, Gentoo provides a set of scripts
which can resolve dependencies, fetch source code, and compile a version of the
package specifically for your needs. We generally only build binaries for
releases and snapshots. The Gentoo Ebuild
HOWTO covers the contents of an ebuild script in detail.
For full ISO releases, we create a full suite of binary packages in an enhanced
.tbz2 format, which is .tar.bz2 compatible with meta-information
attached to the end of the file. These can be used to install a working (though
not fully optimized) version of the package quickly and efficiently.
It is possible to create RPMs (Redhat package manager files) using Gentoo's
Portage, but it is not currently possible to use already existing RPMs to
I want to perform the ./configure step myself. Can I?
Yes, but it is not trivial, nor is it recommended. Since the method to do this
requires a good understanding of Portage internals and commands, it is instead
recommended that you patch the ebuild to do whatever it is that you want and
place it in a Portage overlay (that's why overlays exist). This is much
better for maintainability, and usually easier. See the Ebuild
HOWTO for more information.
How do I use emerge from behind a firewall?
See the questions on proxies, rsync, and downloading source
What if rsync doesn't work for me?
If you're behind a firewall that doesn't permit rsync traffic, then you can use
emerge-webrsync which will fetch and install a Portage snapshot for you
through regular HTTP. See the proxy section of this
document for information on downloading source files and Portage snapshots via
I have only slow modem connection at home. Can I download sources somewhere
else and add them to my system?
Definitely. You can run emerge --pretend package to see what programs
are going to be installed. To find out the sources for those packages and where
to download the sources from, you can run emerge -fp package. Download
sources and bring them on any media home. Put the sources into
/usr/portage/distfiles/ and then simply run emerge package.
Be warned, however, that this is a tedious process.
Source tarballs are collecting in /usr/portage/distfiles/. Is it safe to
delete these files?
Deleting these files will have no negative impact on day-to-day performance.
However, it might be wise to keep the most recent version of the files; often
several ebuilds will be released for the same version of a specific piece of
software. If you have deleted the archive and you upgrade the software it will
be necessary to download them from the internet again.
You can use the eclean script from app-portage/gentoolkit to
manage the contents of /usr/portage/distfiles/ and a few other
locations. Please read man eclean to learn more about its usage, as well
as the Gentoolkit Guide.
What's in /var/tmp/portage? Is it safe to delete the files and
directories in /var/tmp/portage?
During compilation, Gentoo saves the sources of the package in
/var/tmp/portage. These files and folder are usually deleted upon
a successful merge, but this sometimes fails. It is safe to clean out all
contents of this directory if emerge is not running. Just to be sure,
always pgrep emerge before cleaning out this directory.
How do I set up an International Keyboard Layout?
Edit the KEYMAP variable in /etc/conf.d/keymaps. To have
console working correctly with extended characters in your keymap you might
also need to set up variables CONSOLETRANSLATION and CONSOLEFONT
in your /etc/conf.d/consolefont (for further information on
localising your environment, refer to our localisation guide).
Then, either reboot, or restart the keymaps and consolefont scripts:
Code Listing 5.1: Restarting keymaps
# /etc/init.d/keymaps restart
# /etc/init.d/consolefont restart
DNS name resolution works for root only
/etc/resolv.conf has the wrong permissions; chmod it as
Code Listing 5.2: Changing permissions on /etc/resolv.conf
# chmod 0644 /etc/resolv.conf
Why can't my user use their own crontab?
You need to add that user to the cron group.
How do I get numlock to start on boot?
If you work in command line, you only need to rc-update add
numlock default &&/etc/init.d/numlock start.
Each GUI provides different tools for this sort of thing; please check the help
section or online manuals for assistance.
How do I have my terminal cleared when I log out?
To have your terminal cleared, add clear to your
Code Listing 5.3: Clearing the terminal during logout
$ echo clear >> ~/.bash_logout
If you want this to happen automatically when you add a new
user, do the same for the /etc/skel/.bash_logout:
Code Listing 5.4: Making new users their terminal clear on logout
# echo clear >> /etc/skel/.bash_logout
ReiserFS and filesystem corruption issues -- how to fix them, etc
If your ReiserFS partition is corrupt, try booting the Gentoo Install CD and
run reiserfsck --rebuild-tree on the corrupted filesystem. This should
make the filesystem consistent again, although you may have lost some files or
directories due to the corruption.
Where can I report bugs?
Use our Bugzilla. If you are unsure if
your problem is an actual bug, you can visit #gentoo on IRC.
How often are new releases made?
Gentoo's packages are usually updated shortly after the main authors release
new code. As for when Gentoo itself makes new stage/profile/ISO releases, check
our Release Engineering Project page. New
releases are announced on the gentoo-announce mailing list. See the question
on upgrading for more information.
My speaker beeps like crazy. How do I disable console beeps?
Console beeps can be turned off using setterm, like this:
Code Listing 7.1: Using setterm
# setterm -blength 0
If you would like to turn off the console beeps on boot, you need to put this
command in /etc/conf.d/local.start. However, this only disables
beeps for the current terminal. To disable beeps for other terminals, pipe the
command output to the target terminal, like this:
Code Listing 7.2: Using setterm (bis)
# setterm -blength 0 >/dev/vc/1
You need to replace /dev/vc/1 with the terminal you would like to disable
console beeps for.
Where can I find more information about Gentoo Linux?
The official Gentoo documentation can be found at
Can I buy a CD of Gentoo Linux?
If you are not able to download and burn an installation CD yourself, you might
find one through one of our licensed stores. However, most stores have
dropped offering CDs and DVDs as these installation media quickly become
You can find the licensed stores on our Get
This FAQ hasn't answered my question. What do I do now?
A good first step is to browse through the relevant documentation, failing that, the various Gentoo
Linux mailing lists listed on Google.
To search through the Gentoo mailing lists, just enter "site:lists.gentoo.org
foo" to search for "foo". If all else fails, or you just want to hang out with
Gentoo folks, visit us on irc: #gentoo.
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.