doc/en/gentoo-upgrading.xml

<?xml version='1.0' encoding="UTF-8"?>
<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/gentoo-upgrading.xml,v 1.41 2008/07/06 08:00:29 nightmorph Exp $ -->

<guide>
<title>Gentoo Upgrading Guide</title>

<author title="Author">
  <mail link="greg_g@gentoo.org">Gregorio Guidi</mail>
</author>
<author title="Editor">
  <mail link="wolf31o2@gentoo.org">Chris Gianelloni</mail>
</author>
<author title="Editor">
  <mail link="nightmorph@gentoo.org">Joshua Saddler</mail>
</author>

<abstract>
This document explains how new Gentoo releases affect existing installs.
</abstract>

<!-- The content of this document is licensed under the CC-BY-SA license -->
<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
<license/>

<version>2.11</version>
<date>2008-07-06</date>

<chapter>
<title>Gentoo and Upgrades</title>
<section>
<title>Philosophy</title>
<body>

<p>
Here in Gentoo land, the concept of upgrading is quite different compared to 
the rest of the Linux world.  You probably already know that we never got in 
touch with the "classic" way of upgrading software: waiting for a new release, 
downloading it, burning, putting it in the cdrom drive and then following the 
upgrade instructions.
</p>

<p>
You know (being a Gentoo user after all) that this process is extremely 
frustrating for power users that want to live on the bleeding edge.  Even power 
users from other distributions probably share the same feelings, given the 
popularity and spread of tools like apt or apt-rpm which make it 
possible to have quick and frequent updates.  However, no distribution is more 
suited than Gentoo to satisfy these kind of demanding users.  From the 
beginning, Gentoo was designed around the concept of fast, incremental 
updates.
</p>

<p>
Ideally, you install once and never bother with releases: just follow the
instructions in <uri
link="/doc/en/handbook/handbook-x86.xml?part=2&amp;chap=1">A Portage
Introduction</uri> in the <uri link="/doc/en/handbook/">Gentoo Handbook</uri>
that explain how to keep your system up to date.  While that's the way things
usually go, sometimes changes are made to the core system which require updates
to be done manually.
</p>

</body>
</section>
<section>
<title>Releases and Profiles</title>
<body>

<p>
A recurring question about the Gentoo release process is: "Why roll out new
releases frequently, if they are not intended to let users update software?"
There are various reasons:
</p>

<ul>
  <li>
    A new release means new Installation CDs with bugfixes and more features
  </li>
  <li>
    A new release provides an updated set of GRP packages, so that users that
    choose "the fast way" to install (stage3 + precompiled packages) end up
    with a system that is not outdated
  </li>
  <li>
    Finally, a new release may, from time to time, implement some features that
    are incompatible with previous releases
  </li>
</ul>

<p>
When a release includes new incompatible features, or provides a set of core
packages and settings that deeply modify the behavior of the system, we say 
that it provides a new <e>profile</e>.
</p>

<p>
A <e>profile</e> is a set of configuration files, stored in a subdirectory of
<path>/usr/portage/profiles</path>, that describe things such as the ebuilds
that are considered <e>system</e> packages, the default USE flags, the default
mapping for virtual packages, and the architecture on which the system is running.
</p>

<p>
The profile in use is determined by the symbolic link
<path>/etc/make.profile</path>, which points to a subdirectory of
<path>/usr/portage/profiles</path> which holds the profile files.  For 
instance, the default x86 2008.0 profile can be found 
at <path>/usr/portage/profiles/default/linux/x86/2008.0</path>.
The files in the parent directories are part of the profile as well (and 
are therefore shared by different subprofiles). This is why we call these
<e>cascaded profiles</e>.
</p>

<p>
Profiles obsoleted by new ones are kept in <path>/usr/portage/profiles</path>
along with the current ones, but they are marked as deprecated.  When that 
happens a file named <path>deprecated</path> is put in the profile directory.
The content of this file is the name of the profile that should be "upgraded 
to"; Portage uses this information to automatically warn you when you should 
update to a new profile.
</p>

<p>
There are various reasons that a new profile may be created: the release of 
new versions of core packages (such as <c>baselayout</c>, <c>gcc</c>, or 
<c>glibc</c>) that are incompatible with previous versions, a change in 
the default USE flags or in the virtual mappings, or maybe a change in 
system-wide settings.
</p>

</body>
</section>
</chapter>

<chapter>
<title>Keeping up with new releases</title>
<section>
<title>Releases without profile changes</title>
<body>

<p>
If a new Gentoo release does not include a new profile then you can safely
pretend that it never happened. :)
</p>

<p>
If you update your installed packages 
<uri link="/doc/en/handbook/handbook-x86.xml?part=2&amp;chap=1">as explained in
the Gentoo Handbook</uri>, then your system will be exactly the same as one
that has been installed using the new release.
</p>

</body>
</section>
<section>
<title>Releases with profile changes</title>
<body>

<p>
If a release (such as 2008.0 for x86) introduces a new profile, you have the
choice to migrate to the new profile.
</p>

<p>
Naturally, you are not forced to do so, and you can continue to use the old 
profile and just update your packages
<uri link="/doc/en/handbook/handbook-x86.xml?part=2&amp;chap=1">as explained 
in the Gentoo Handbook</uri>.
</p>

<p>
However, Gentoo strongly recommends updating your profile if it becomes 
deprecated.  When this happens, it means that Gentoo developers no longer
plan on supporting it.
</p>

<p>
If you decide to migrate to the new profile, then you will have to manually
perform the update.  The way you update may vary significantly from release 
to release; it depends on how deep the modifications introduced in the new
profile are.
</p>

<p>
In the simplest case you only have to change the <path>/etc/make.profile</path>
symlink, in the worst case you may have to recompile your system from scratch
while doing a neat voodoo dance.  Migration is usually covered in the release
notes. You can also find <uri link="#instructions">instructions</uri> at the
end of this guide.
</p>

</body>
</section>
<section>
<title>Supported profiles</title>
<body>

<p>
You can view the list of profiles on your architecture officially supported by
Gentoo developers when you <c>emerge eselect</c> and then run the following
command:
</p>

<pre caption="Viewing supported profiles">
# <i>eselect profile list</i>
</pre>

</body>
</section>
</chapter>

<chapter id="instructions">
<title>Profile updating instructions</title>
<section id="general">
<title>General instructions</title>
<body>

<impo>
Make sure your Portage is updated before performing any profile changes.
</impo>

<p>
First, run <c>emerge eselect</c>. The <c>eselect</c> utility will let you view
and select profiles easily, without needing to create or remove symlinks by
hand.
</p>

<pre caption="Profile selection with eselect">
<comment>(View available profiles)</comment>
# <i>eselect profile list</i>

<comment>(Select the number of your desired profile from the list)</comment>
# <i>eselect profile set &lt;number&gt;</i>
</pre>

<p>
If you'd still prefer to change profiles manually, then simply do the following:
</p>

<pre caption="Changing profiles manually">
# <i>rm /etc/make.profile</i>
# <i>ln -s ../usr/portage/profiles/</i>&lt;selected profile&gt;<i> /etc/make.profile</i>
</pre>

<note>
There are <b>desktop</b> and <b>server</b> subprofiles for most architectures.
Examine these profiles carefully, as they may serve your needs better than the
extremely minimal default profiles.
</note>

<note>
The <c>developer</c> subprofile is specifically for Gentoo Linux development
tasks. It is <e>not</e> meant to help set up general development environments.
</note>

</body>
</section>
<section>
<title>Updating to 2008.0, 2007.0, or 2006.1</title>
<body>

<p>
If you intend to upgrade to these profiles, you should be aware that they expect
the system to be set to a Unicode locale by default; specifically that
UNICODE="yes" is set in <path>/etc/rc.conf</path>. For this to work, you must
have created a Unicode locale for your system to use. Please read our <uri
link="/doc/en/utf-8.xml">UTF-8 guide</uri> to learn how to create the proper
locale.
</p>

<p>
Alternatively, if you do not wish to set a locale, you should specify
UNICODE="no" in <path>/etc/rc.conf</path>, and re-emerge <c>baselayout</c> (or
wait until your next <c>baselayout</c> update) with the <c>-unicode</c> USE
flag. You can set <c>-unicode</c> just for <c>baselayout</c>, or you can set it
globally for all packages by adding it to your USE variable in
<path>/etc/make.conf</path>.
</p>

<pre caption="Optional: removing Unicode support">
<comment>(To remove Unicode support just for baselayout)</comment>
# <i>echo "sys-apps/baselayout -unicode" >> /etc/portage/package.use</i>
# <i>emerge -a baselayout</i>

<comment>(To remove Unicode support from your whole system)</comment>
# <i>nano -w /etc/make.conf</i>
USE="-unicode"
# <i>emerge -a baselayout</i>
</pre>

<note>
If you are updating to a 2007.0 profile on the Sparc architecture, then you will
need to follow the <uri link="/doc/en/gcc-upgrading.xml">GCC Upgrading
Guide</uri>, as <c>gcc-4</c> is the default compiler.
</note>

<p>
Finally, follow the <uri link="#general">general instructions</uri> for updating
your profile.
</p>

</body>
</section>
<section>
<title>Updating to 2006.0</title>
<body>

<p>
To switch to the 2006.0 profile, point the <path>/etc/make.profile</path>
symlink to the new location. Make sure your Portage is updated before you
change your profile.
</p>

<pre caption="Changing to a 2006.0 profile">
# <i>rm /etc/make.profile</i>
# <i>ln -s ../usr/portage/profiles/</i>&lt;selected profile&gt;<i> /etc/make.profile</i>
</pre>

<p>
<b>alpha</b> - Users that use a 2.4 kernel or don't want to use NPTL should use
the default-linux/alpha/no-nptl profile.  More information is available in <uri
link="/proj/en/releng/release/2006.0/alpha-release-notes.xml">the alpha release
notes</uri>.
</p>

<p>
<b>ppc</b> - The merge of the ppc32 and ppc64 profiles went forward. The ppc32
profile has been changed in a way that offers a minimalistic generic profile
for all purposes, located in default-linux/ppc/ppc32. The release-dependent
profile is optimized for desktop-usage and located in
default-linux/ppc/ppc32/2006.0. There are some subprofiles available for G3 and
G4 processors, and G3/Pegasos and G4/Pegasos for the Pegasos Open Desktop
Workstation. Make sure you choose the correct subprofile for your system when
migrating to a 2006.0 profile.
</p>

<p>
<b>sparc</b> - Upgrading to the <b>2.4</b>-kernel based 2006.0/2.4 profile
requires manual user intervention (unmerging java stuff) and an <c>emerge -e
world</c> because of the <uri link="/doc/en/gcc-upgrading.xml">gcc
upgrade</uri>.<br/>
Upgrading to the <b>2.6</b>-kernel based 2006.0 profile which is not considered
stable also requires an entry in <path>/etc/portage/package.unmask</path> to
umask a 2.6 version of <c>gentoo-sources</c> and a full rebuild.
</p>

<p>
<b>All other archs</b> - There are no fundamental changes in this profile. No
specific action needs to be performed.
</p>

</body>
</section>
<section>
<title>Updating to 2005.1</title>
<body>

<p>
To switch to the 2005.1 profile, point the <path>/etc/make.profile</path>
symlink to the new location. Make sure your Portage is updated before you
change your profile.
</p>

<pre caption="Changing to a 2005.1 profile">
# <i>rm /etc/make.profile</i>
# <i>ln -s ../usr/portage/profiles/</i>&lt;selected profile&gt;<i> /etc/make.profile</i>
</pre>

<p>
<b>All archs</b> - There are no fundamental changes in this profile. No
specific action needs to be performed.
</p>

<p>
<b>ppc</b> - With the 2005.1 release, the ppc and ppc64 profiles were merged
and a number of subprofiles for specific subarchitectures were created. Make
sure you choose the correct subprofile for your system when migrating to a
2005.1 profile.
</p>

</body>
</section>
<section>
<title>Updating to 2005.0</title>
<body>

<p>
With the introduction of 2005.0, several architectures have decided to define
additional profiles. Make sure you read the description of said profiles before
you decide to migrate to one of them. Most architectures now also default to the
2.6 kernel tree where 2.4 was chosen previously.
</p>

<p>
Some architectures require a bit more actions to be completed in order to
convert from one profile to another. If that is the case, the step-by-step
guides are linked from the table.
</p>

<table>
<tr>
  <th>Profile</th>
  <th>Description</th>
  <th>Specific Upgrade Guide</th>
</tr>
<tr>
  <ti>default-linux/alpha/2005.0</ti>
  <ti>Default Alpha 2005.0 profile for 2.6 kernels</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/alpha/2005.0/2.4</ti>
  <ti>Alpha 2005.0 profile for 2.4 kernels</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/amd64/2005.0</ti>
  <ti>Default AMD64 2005.0 profile for 2.6 kernels</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/amd64/2005.0/no-multilib</ti>
  <ti>AMD64 2005.0 profile for multilib-disabled system installations</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/arm/2005.0</ti>
  <ti>Default ARM 2005.0 profile for 2.6 kernels</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/hppa/2005.0</ti>
  <ti>Default HPPA 2005.0 profile for 2.6 kernels</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/hppa/2005.0/2.4</ti>
  <ti>HPPA 2005.0 profile for 2.4 kernels</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/mips/2005.0</ti>
  <ti>Default MIPS 2005.0 profile</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/mips/cobalt/2005.0</ti>
  <ti>Cobalt specific MIPS 2005.0 profile</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/mips/mips64/n32/2005.0</ti>
  <ti>2005.0 profile for n32-supporting MIPS platforms</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/mips/mips64/ip28/2005.0</ti>
  <ti>Indigo2 Impact specific 64-bit 2005.0 profile</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/mips/mips64/2005.0</ti>
  <ti>64-bit MIPS 2005.0 profile</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/ppc/2005.0</ti>
  <ti>Default PPC 2005.0 profile for 2.6 kernels</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/ppc64/2005.0</ti>
  <ti>Default PPC64 2005.0 profile for 2.6 kernels</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/s390/2005.0</ti>
  <ti>Default S390 2005.0 profile</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/sparc/sparc32/2005.0</ti>
  <ti>Default Sparc 32-bit 2005.0 profile</ti>
  <ti></ti>
</tr>
<!-- http://dev.gentoo.org/~dsd/kernel-2.6.htm 
     No subprofiles for sparc
<tr>
  <ti>default-linux/sparc/sparc32/2005.0/2.6</ti>
  <ti>Sparc 32-bit 2005.0 profile for 2.6 kernels</ti>
  <ti></ti>
</tr>
-->
<tr>
  <ti>default-linux/sparc/sparc64/2005.0</ti>
  <ti>Default Sparc 64-bit 2005.0 profile</ti>
  <ti></ti>
</tr>
<!-- http://dev.gentoo.org/~dsd/kernel-2.6.htm
     No subprofiles for sparc
<tr>
  <ti>default-linux/sparc/sparc64/2005.0/2.6</ti>
  <ti>Sparc 64-bit 2005.0 profile for 2.6 kernels</ti>
  <ti></ti>
</tr>
-->
<tr>
  <ti>default-linux/x86/2005.0</ti>
  <ti>Default x86 2005.0 profile for 2.6 kernels</ti>
  <ti></ti>
</tr>
<tr>
  <ti>default-linux/x86/2005.0/2.4</ti>
  <ti>x86 2005.0 profile for 2.4 kernels</ti>
  <ti></ti>
</tr>
</table>

<p>
To switch to the selected profile, point the <path>/etc/make.profile</path>
symlink to the new location. Make sure your Portage is updated before you change
your profile!
</p>

<pre caption="Changing to a 2005.0 profile">
# <i>rm /etc/make.profile</i>
# <i>ln -s ../usr/portage/profiles/</i>&lt;selected profile&gt;<i> /etc/make.profile</i>
</pre>

<p>
If you are running a Linux 2.4-based system but want to migrate to a 2.6-based
kernel, make sure you read our <uri link="/doc/en/migration-to-2.6.xml">Gentoo
Linux 2.6 Migration Guide</uri>.
</p>

</body>
</section>
<section>
<title>Updating to 2004.3</title>
<body>

<p>
With the introduction of the 2004.3 profiles, users are not going to see huge
modifications of their systems (see below for details). However, Gentoo
developers decided to push out this new profile and to deprecate quite a few of
the old ones to speed up the adoption of <e>stacked profiles</e>, that is, the
profiles that follow the new layout of the <path>/usr/portage/profiles</path>
directory, for instance
<path>/usr/portage/profiles/default-linux/x86/2004.3</path> (supported by
Portage 2.0.51 or later).
</p>

<p>
To switch to the 2004.3 profile, point the <path>/etc/make.profile</path>
symlink to the new location:
</p>

<warn>
Don't forget to upgrade Portage <e>before</e> you change your profile!!!
</warn>

<pre caption="Updating the /etc/make.profile symlink">
<comment>substitute &lt;arch&gt; with your arch</comment>
# <i>rm /etc/make.profile</i>
# <i>ln -s ../usr/portage/profiles/default-linux/&lt;arch&gt;/2004.3 /etc/make.profile</i>
</pre>

<p>
<b>All archs</b> - As said above, there are no big changes introduced in this
profile. However, it should be noted that <c>sys-apps/slocate</c> and
<c>net-misc/dhcpcd</c> are no longer considered system packages. This means
that if you run <c>emerge --depclean</c>, Portage will try to remove them from
your system. If you need any of those packages, add them to
<path>/var/lib/portage/world</path> after the profile switch, or manually
emerge them.
</p>

<p>
<b>ppc</b> - <c>sys-fs/udev</c> is now the default instead of 
<c>sys-fs/devfs</c> for newly installed machines. This has no 
effect on already installed machines, though.
</p>

</body>
</section>
<section>
<title>Updating Portage to Support Cascading Profiles</title>
<body>

<p>
Although this section does not seem to integrate well in this upgrading guide,
it is quite important. Any profile listed above this section requires a Portage
version that supports cascading profiles. However, some obsoleted profiles don't
allow the user to upgrade Portage or the user is using a profile that isn't
available anymore - any attempt to upgrade Portage will result in a failure.
</p>

<p>
To work around this problem, users can set a temporary symbolic link to the
<e>obsolete</e> profile, allowing them to upgrade their Portage after which
they can continue with the upgrade procedure set forth in this guide. Please
substitute <c>&lt;arch&gt;</c> with your respective architecture:
</p>

<pre caption="Updating Portage through the obsolete profile">
# <i>rm /etc/make.profile</i>
# <i>cd /etc</i>
# <i>ln -sf ../usr/portage/profiles/obsolete/&lt;arch&gt; make.profile</i>
# <i>emerge -n '>=sys-apps/portage-2.0.51'</i>
</pre>

</body>
</section>
<section>
<title>Updating to 2004.2</title>
<body>

<p>
To switch to the 2004.2 profile, point the <path>/etc/make.profile</path> 
symlink to the new location:
</p>

<warn>
Don't forget to upgrade Portage <e>before</e> you change your profile!!!
</warn>

<pre caption="Updating the /etc/make.profile symlink">
<comment>substitute &lt;arch&gt; with your arch</comment>
# <i>rm /etc/make.profile</i>
# <i>ln -s ../usr/portage/profiles/default-linux/&lt;arch&gt;/2004.2 /etc/make.profile</i>
</pre>

<p>
<b>x86</b> - This profile changes the default X11 implementation from
<c>x11-base/xfree</c> to <c>x11-base/xorg-x11</c>.  This change only touches
the <e>default</e> value, and is only relevant for those who have not installed
an X server yet.  If you already have one installed, then it will not affect
you at all; you are free to switch from one X server to the other exactly as
before.
</p>

<p>
<b>amd64</b> - There are no fundamental changes from previous profiles, no
specific action needs to be performed.
</p>

</body>
</section>
<section>
<title>Updating to 2004.0</title>
<body>

<p>
To switch to the 2004.0 profile, point the <path>/etc/make.profile</path> 
symlink to the new location:
</p>

<pre caption="Updating the /etc/make.profile symlink">
<comment>substitute &lt;arch&gt; with your arch</comment>
# <i>rm /etc/make.profile</i>
# <i>ln -s ../usr/portage/profiles/default-&lt;arch&gt;-2004.0 /etc/make.profile</i>
</pre>

<p>
<b>All archs</b> - There are no fundamental changes from previous profiles, no
specific action needs to be performed.
</p>

</body>
</section>
<section>
<title>Updating from profiles older than 1.4 to 1.4</title>
<body>

<p>
The instructions for this upgrade are quite complex, you can find them
<uri link="/doc/en/new-upgrade-to-gentoo-1.4.xml">here</uri>.
</p>

</body>
</section>
</chapter>

</guide>