2.4 2005-05-07
Chrooting Optional: Selecting Mirrors

In order to download source code quickly it is recommended to select a fast mirror. Portage will look in your make.conf file for the GENTOO_MIRRORS variable and use the mirrors listed therein. You can surf to our mirror list and search for a mirror (or mirrors) close to you (as those are most frequently the fastest ones), but we provide a nice tool called mirrorselect which provides you with a nice interface to select the mirrors you want.

# mirrorselect -i -o >> /mnt/gentoo/etc/make.conf
Do not select any IPv6 mirrors. Our stages currently do not support IPv6.

A second important setting is the SYNC setting in make.conf. This variable contains the rsync server you want to use when updating your Portage tree (the collection of ebuilds, scripts containing all the information Portage needs to download and install software). Although you can manually enter a SYNC server for yourself, mirrorselect can ease that operation for you:

# mirrorselect -i -r -o >> /mnt/gentoo/etc/make.conf

After running mirrorselect it is adviseable to double-check the settings in /mnt/gentoo/etc/make.conf !

Copy DNS Info

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.

(The "-L" option is needed to make sure we don't copy a symbolic link)
# cp -L /etc/resolv.conf /mnt/gentoo/etc/resolv.conf
Mounting the proc Filesystem

Mount the /proc filesystem on /mnt/gentoo/proc to allow the installation to use the kernel-provided information even within the chrooted environment.

# mount -t proc none /mnt/gentoo/proc
Entering the new 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 (Installation CD 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.

# chroot /mnt/gentoo /bin/bash
# env-update
 * Caching service dependencies...
# source /etc/profile

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 :-)

Updating the Portage tree

You should now update your Portage tree to the latest version. emerge --sync does this for you.

# emerge --sync

If you are behind a firewall that blocks rsync traffic, you can use emerge-webrsync which will download and install a portage snapshot for you.

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.

Choosing the Right Profile

First, a small definition is in place.

A profile is a building block for any Gentoo system. Not only does it specify default values for CHOST, CFLAGS and other important variables, it also locks the system to a certain range of package versions. This is all maintained by the Gentoo developers.

Previously, such a profile was barely touched by the user. However, recently, x86, hppa and alpha users can choose between two profiles, one for a 2.4 kernel and one for a 2.6 kernel. This requirement has been imposed to improve the integration of the 2.6 kernels.

You can see what profile you are currently using by issuing the following command:

# ls -l /etc/make.profile
lrwxrwxrwx  1 root root 48 Mar  7 11:55 /etc/make.profile ->
      ../usr/portage/profiles/default-linux/x86/2005.0

If you are using one of the aforementioned three architectures, you will see an additional profile in the one listed by the make.profile symlink:

# ls -F /etc/make.profile/
2.4/  packages  parent  virtuals

As you can see, in the above example there is a 2.4 subdirectory. This means that the current profile uses the 2.6 kernel; if you want a 2.4-based system, you need to relink your make.profile symlink:

# ln -snf /usr/portage/profiles/default-linux/x86/2005.0/2.4 /etc/make.profile
Configuring the USE variable

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 the make.defaults files of your profile. You will find make.defaults files in the directory which /etc/make.profile points to and all parent directories as well. The default USE setting is the sum of all USE settings in all make.defaults files. 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.

# less /usr/portage/profiles/use.desc
(You can scroll using your arrow keys, exit by pressing 'q')

As an example we show a USE setting for a KDE-based system with DVD, ALSA and CD Recording support:

# nano -w /etc/make.conf
USE="-gtk -gnome qt kde dvd alsa cdr"
Optional: GLIBC Locales

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. Only do this if you know what locales to choose. This will not work for the bootstrapping, but when you recompile glibc afterwards it will.

# mkdir /etc/portage
# echo "sys-libs/glibc userlocales" >> /etc/portage/package.use

Now specify the locales you want to be able to use:

# nano -w /etc/locales.build

The following locales are an example to get both English (United States) and German (Germany) with the accompanying character formats (like UTF-8).

en_US/ISO-8859-1
en_US.UTF-8/UTF-8
de_DE/ISO-8859-1
de_DE@euro/ISO-8859-15
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.

Progressing from Stage1 to Stage2 Introduction to Bootstrapping

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, you might want to download all necessary sourcecode first. If you do not want to do this, 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. 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.

# cd /usr/portage
# scripts/bootstrap.sh -f
Bootstrapping the System

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.

# cd /usr/portage
# scripts/bootstrap.sh

Now continue with the next step, Progressing from Stage2 to Stage3.

Progressing from Stage2 to Stage3 Introduction

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 --emptytree 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.

# emerge --pretend --emptytree system | less

Note that, if you haven't touched the default CFLAGS/CXXFLAGS setting, using emerge --pretend --newuse system is sufficient: it will rebuild the applications that are affected by a change in USE flags (compared to the USE flag we used while building the stage2). If you didn't touch the USE flag either, why are you running a stage2 installation then?

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.

# emerge --fetchonly --emptytree system
Building the System

To start building the system, execute emerge --emptytree system. Then go do something to keep your mind busy, because this step takes a long time to complete.

# emerge --emptytree system

Again, if you haven't touched the default CFLAGS and CXXFLAGS setting, using --newuse is sufficient.

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.