en/handbook/hb-install-config.xml

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<sections>

<abstract>
You need to edit some important configuration files. In this chapter
you receive an overview of these files and an explanation on how to
proceed.
</abstract>

<version>34</version>
<date>2013-12-18</date>

<section>
<title>Filesystem Information</title>
<subsection>
<title>What is fstab?</title>
<body>

<p>
Under Linux, all partitions used by the system must be listed in
<path>/etc/fstab</path>. This file contains the mount points 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.)
</p>

</body>
</subsection>
<subsection>
<title>Creating /etc/fstab</title>
<body>

<p>
<path>/etc/fstab</path> 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:
</p>

<ul>
<li>
  The first field shows the <b>partition</b> described (the path to the device
  file)
</li>
<li>
  The second field shows the <b>mount point</b> at which the partition should be
  mounted
</li>
<li>
  The third field shows the <b>filesystem</b> used by the partition
</li>
<li>
  The fourth field shows the <b>mount options</b> used by <c>mount</c> when it
  wants to mount the partition. As every filesystem has its own mount options,
  you are encouraged to read the mount man page (<c>man mount</c>) for a full
  listing. Multiple mount options are comma-separated.
</li>
<li>
  The fifth field is used by <c>dump</c> to determine if the partition needs to
  be <b>dump</b>ed or not. You can generally leave this as <c>0</c> (zero).
</li>
<li>
  The sixth field is used by <c>fsck</c> to determine the order in which 
  filesystems should be <b>check</b>ed if the system wasn't shut down properly. 
  The root filesystem should have <c>1</c> while the rest should have <c>2</c> 
  (or <c>0</c> if a filesystem check isn't necessary).
</li>
</ul>

<impo>
The default <path>/etc/fstab</path> file provided by Gentoo <e>is not a valid
fstab file</e>. You <b>have to create</b> your own <path>/etc/fstab</path>.
</impo>

<pre caption="Opening /etc/fstab">
# <i>nano -w /etc/fstab</i>
</pre>

<p>
In the remainder of the text, we use the default <path>/dev/sd*</path> block
device files as partition. You can also opt to use the symbolic links in the
<path>/dev/disk/byid</path> or <path>/dev/disk/by-uuid</path>. These names are
not likely to change, whereas the default block device files naming depends on
a number of factors (such as how and in what order the disks are attached to
your system). However, if you do not intend to fiddle with the disk ordering,
you can continue with the default block device files safely.
</p>

</body>
<body test="func:keyval('/boot')">

<p>
Let us take a look at how we write down the options for the <path>/boot</path>
partition. This is just an example, if you didn't or couldn't create a
<path>/boot</path>, don't copy it.
</p>

<p>
In our default <keyval id="arch"/> partitioning example, <path>/boot</path> is
usually the <path><keyval id="/boot"/></path> partition, with <c>ext2</c> as
filesystem. It needs to be checked during boot, so we would write down:
</p>

<pre caption="An example /boot line for /etc/fstab">
<keyval id="/boot"/>   /boot     ext2    defaults        0 2
</pre>

<p>
Some users don't want their <path>/boot</path> partition to be mounted
automatically to improve their system's security. Those people should 
substitute <c>defaults</c> with <c>noauto</c>. This does mean that you need to 
manually mount this partition every time you want to use it.
</p>

</body>
<body>

<p>
Add the rules that match your partitioning scheme and append rules for
your CD-ROM drive(s), and of course, if you have other partitions or drives, 
for those too.
</p>

<p>
Now use the <e>example</e> below to create your <path>/etc/fstab</path>:
</p>

<pre caption="A full /etc/fstab example" test="func:keyval('arch')='HPPA' or func:keyval('arch')='x86' or func:keyval('arch')='AMD64'">
<keyval id="/boot"/>   /boot        ext2    defaults,noatime     0 2
/dev/sda3   none         swap    sw                   0 0
/dev/sda4   /            ext4    noatime              0 1

/dev/cdrom  /mnt/cdrom   auto    noauto,user          0 0
</pre>

<pre caption="A full /etc/fstab example" test="func:keyval('arch')='Alpha' or func:keyval('arch')='MIPS'">
<keyval id="/boot"/>   /boot        ext2    defaults,noatime     0 2
/dev/sda2   none         swap    sw                   0 0
/dev/sda3   /            ext4    noatime              0 1

/dev/cdrom  /mnt/cdrom   auto    noauto,user          0 0
</pre>

<pre caption="A full /etc/fstab example" test="func:keyval('arch')='SPARC'">
/dev/sda1   /               ext4        noatime              0 1
/dev/sda2   none            swap        sw                   0 0
/dev/sda4   /usr            ext4        noatime              0 2
/dev/sda5   /var            ext4        noatime              0 2
/dev/sda6   /home           ext4        noatime              0 2

<comment># You must add the rules for openprom</comment>
openprom    /proc/openprom  openpromfs  defaults             0 0

/dev/cdrom  /mnt/cdrom      auto        noauto,user          0 0
</pre>

<pre caption="A full /etc/fstab example" test="func:keyval('arch')='PPC' or
func:keyval('arch')='PPC64'">
/dev/sda4   /            ext4    noatime              0 1
/dev/sda3   none         swap    sw                   0 0

/dev/cdrom  /mnt/cdrom   auto    noauto,user          0 0
</pre>

<p>
<c>auto</c> makes <c>mount</c> guess for the filesystem (recommended for 
removable media as they can be created with one of many filesystems) and 
<c>user</c> makes it possible for non-root users to mount the CD.
</p>

<p>
To improve performance, most users would want to add the <c>noatime</c>
mount option, which results in a faster system since access times
aren't registered (you don't need those generally anyway). This is also
recommended for solid state drive (SSD) users, who should also enable
the <c>discard</c> mount option (ext4 and btrfs only for now) which
makes the TRIM command work.
</p>

<p>
Double-check your <path>/etc/fstab</path>, save and quit to continue.
</p>

</body>
</subsection>
</section>
<section>
<title>Networking Information</title>
<subsection>
<title>Host name, Domainname, etc</title>
<body>

<p>
One of the choices the user has to make is name his/her PC. This seems to be 
quite easy, but <e>lots</e> 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
<c>tux</c> and domain <c>homenetwork</c>. 
</p>

<pre caption="Setting the host name">
# <i>nano -w /etc/conf.d/hostname</i>

<comment>(Set the hostname variable to your host name)</comment>
hostname="<i>tux</i>"
</pre>

<p>
Second, <e>if</e> you need a domainname, set it in <path>/etc/conf.d/net</path>.
You only need a domain if your ISP or network administrator says so, or if you
have a DNS server but not a DHCP server. You don't need to worry about DNS or
domainnames if your networking is setup for DHCP.
</p>

<note>
The <path>/etc/conf.d/net</path> file does not exist by default, so you might
need to create it.
</note>

<pre caption="Setting the domainname">
# <i>nano -w /etc/conf.d/net</i>

<comment>(Set the dns_domain variable to your domain name)</comment>
dns_domain_lo="<i>homenetwork</i>"
</pre>

<note>
If you choose not to set a domainname, you can get rid of the "This is
hostname.(none)" messages at your login screen by editing
<path>/etc/issue</path>. Just delete the string <c>.\O</c> from that file.
</note>

<p>
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:
</p>

<pre caption="Setting the NIS domainname">
# <i>nano -w /etc/conf.d/net</i>

<comment>(Set the nis_domain variable to your NIS domain name)</comment>
nis_domain_lo="<i>my-nisdomain</i>"
</pre>

<note>
For more information on configuring DNS and NIS, please read the examples
provided in <path>/usr/share/doc/netifrc-*/net.example.bz2</path> which
can be read using <c>bzless</c>. Also, you may want to emerge <c>openresolv</c>
to help manage your DNS/NIS setup.
</note>

</body>
</subsection>
<subsection>
<title>Configuring your Network</title>
<body>

<p>
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.
</p>

<note>
More detailed information about networking, including advanced topics like
bonding, bridging, 802.1Q VLANs or wireless networking is covered in the <uri
link="?part=4">Gentoo Network Configuration</uri> section.
</note>

<p>
All networking information is gathered in <path>/etc/conf.d/net</path>. 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. A fully
commented example that covers many different configurations is available in
<path>/usr/share/doc/netifrc-*/net.example.bz2</path>.
</p>

<p>
DHCP is used by default. For DHCP to work, you will need to install a DHCP
client. This is described later in <uri
link="?part=1&amp;chap=9#networking-tools">Installing Necessary System
Tools</uri>. Do not forget to install a DHCP client.
</p>

<p>
If you need to configure your network connection either because you need
specific DHCP options or because you do not use DHCP at all, open
<path>/etc/conf.d/net</path> with your favorite editor (<c>nano</c> is used in
this example):
</p>

<pre caption="Opening /etc/conf.d/net for editing">
# <i>nano -w /etc/conf.d/net</i>
</pre>

<p>
To enter your own IP address, netmask and gateway, you need
to set both <c>config_eth0</c> and <c>routes_eth0</c>:
</p>

<note>
This assumes that your network interface will be called eth0. This is, however,
very system dependent. It is recommended to assume that the interface is named
the same as the interface name when booted from the installation media <e>if</e>
the installation media is sufficiently recent. More information can be found in
<uri link="?part=4&amp;chap=2#doc_chap4">Network Interface Naming</uri>.
</note>

<pre caption="Manually setting IP information for eth0">
config_eth0="192.168.0.2 netmask 255.255.255.0 brd 192.168.0.255"
routes_eth0="default via 192.168.0.1"
</pre>

<p>
To use DHCP, define <c>config_eth0</c>:
</p>

<pre caption="Automatically obtaining an IP address for eth0">
config_eth0="dhcp"
</pre>

<p>
Please read <path>/usr/share/doc/netifrc-*/net.example.bz2</path> for a
list of all available options. Be sure to also read your DHCP client manpage if
you need to set specific DHCP options.
</p>

<p>
If you have several network interfaces repeat the above steps for 
<c>config_eth1</c>, <c>config_eth2</c>, etc.
</p>

<p>
Now save the configuration and exit to continue.
</p>

</body>
</subsection>
<subsection>
<title>Automatically Start Networking at Boot</title>
<body>

<p>
To have your network interfaces activated at boot, you need to add them to the
default runlevel.
</p>

<pre caption="Adding net.eth0 to the default runlevel">
# <i>cd /etc/init.d</i>
# <i>ln -s net.lo net.eth0</i>
# <i>rc-update add net.eth0 default</i>
</pre>

<p>
If you have several network interfaces, you need to create the appropriate
<path>net.*</path> files just like you did with <path>net.eth0</path>.
</p>

<p>
If you later find out the assumption about the network interface name (which we
currently document as eth0) was wrong, then
</p>

<ol>
<li>
update the <path>/etc/conf.d/net</path> file with the correct interface name (like enp3s0
instead of eth0),
</li>
<li>
create new symbolic link (like <path>/etc/init.d/net.enp3s0</path>),
</li>
<li>
remove the old symbolic link (<c>rm /etc/init.d/net.eth0</c>), 
</li>
<li>
add the new one to the default runlevel, and
</li>
<li>
remove the old one using <c>rc-update del net.eth0 default</c>.
</li>
</ol>

</body>
</subsection>
<subsection>
<title>Writing Down Network Information</title>
<body>

<p>
You now need to inform Linux about your network. This is defined in
<path>/etc/hosts</path> and helps in resolving host names to IP addresses for
hosts that aren't resolved by your nameserver.  You need to define your system.
You may also want to define other systems on your network if you don't want to
set up your own internal DNS system.
</p>

<pre caption="Opening /etc/hosts">
# <i>nano -w /etc/hosts</i>
</pre>

<pre caption="Filling in the networking information">
<comment>(This defines the current system)</comment>
127.0.0.1     tux.homenetwork tux localhost

<comment>(Define extra systems on your network,
they need to have a static IP to be defined this way.)</comment>
192.168.0.5   jenny.homenetwork jenny
192.168.0.6   benny.homenetwork benny
</pre>

<p>
Save and exit the editor to continue.
</p>

<p test="func:keyval('arch')='AMD64' or func:keyval('arch')='x86' or substring(func:keyval('arch'),1,3)='PPC'">
If you don't have PCMCIA, you can now continue with <uri
link="#sysinfo">System Information</uri>. PCMCIA-users should read the
following topic on PCMCIA.
</p>

</body>
</subsection>
<subsection test="func:keyval('arch')='AMD64' or func:keyval('arch')='x86' or substring(func:keyval('arch'),1,3)='PPC'">
<title>Optional: Get PCMCIA Working</title>
<body>

<p>
PCMCIA users should first install the <c>pcmciautils</c> package.
</p>

<pre caption="Installing pcmciautils">
# <i>emerge pcmciautils</i>
</pre>

</body>
</subsection>
</section>

<section id="sysinfo">
<title>System Information</title>
<subsection>
<title>Root Password</title>
<body>

<p>
First we set the root password by typing:
</p>

<pre caption="Setting the root password">
# <i>passwd</i>
</pre>

</body>
</subsection>
<subsection>
<title>System Information</title>
<body>

<p>
Gentoo uses <path>/etc/rc.conf</path> to configure the services, startup,
and shutdown of your system. Open up <path>/etc/rc.conf</path> and enjoy all
the comments in the file.
</p>

<pre caption="Configuring services">
# <i>nano -w /etc/rc.conf</i>
</pre>

<p>
When you're finished configuring these two files, save them and exit. 
</p>

<p>
Gentoo uses <path>/etc/conf.d/keymaps</path> to handle keyboard configuration.
Edit it to configure your keyboard.
</p>

<pre caption="Opening /etc/conf.d/keymaps">
# <i>nano -w /etc/conf.d/keymaps</i>
</pre>

<p>
Take special care with the <c>keymap</c> variable. If you select the wrong
<c>keymap</c>, you will get weird results when typing on your keyboard.
</p>

<note test="substring(func:keyval('arch'),1,3)='PPC'">
PPC uses x86 keymaps on most systems.
</note>

<p>
When you're finished configuring <path>/etc/conf.d/keymaps</path>, save and
exit. 
</p>

<p>
Gentoo uses <path>/etc/conf.d/hwclock</path> to set clock options. Edit it
according to your needs.
</p>

<pre caption="Opening /etc/conf.d/hwclock">
# <i>nano -w /etc/conf.d/hwclock</i>
</pre>

<p>
If your hardware clock is not using UTC, you need to add <c>clock="local"</c>
to the file. Otherwise you will notice some clock skew.
</p>

<p>
When you're finished configuring <path>/etc/conf.d/hwclock</path>, save and
exit. 
</p>

</body>
</subsection>

<subsection>
<title>Configure locales</title>
<body>

<p>
You will probably only use one or maybe two locales on your system. You have to
specify locales you will need in <path>/etc/locale.gen</path>.
</p>

<pre caption="Opening /etc/locale.gen">
# <i>nano -w /etc/locale.gen</i>
</pre>

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

<pre caption="Specify your locales">
en_US ISO-8859-1
en_US.UTF-8 UTF-8
de_DE ISO-8859-1
de_DE@euro ISO-8859-15
</pre>

<note>
You can select your desired locales in the list given by running <c>locale -a</c>.
</note>

<warn>
We strongly suggest that you should use at least one UTF-8 locale because some
applications may require it.
</warn>

<p>
The next step is to run <c>locale-gen</c>. It will generates all the locales you
have specified in the <path>/etc/locale.gen</path> file.
</p>

<pre caption="Running locale-gen">
# <i>locale-gen</i>
</pre>

<p>
You can verify that your selected locales are available by running <c>locale -a</c>.
</p>

<p>
Once done, you now have the possibility to set the system-wide locale settings.
With <c>eselect locale list</c>, the available targets are displayed:
</p>

<pre caption="Displaying the available LANG settings">
# <i>eselect locale list</i>
Available targets for the LANG variable:
  [1] C
  [2] POSIX
  [3] en_US
  [4] en_US.iso88591
  [5] en_US.utf8
  [6] de_DE
  [7] de_DE.iso88591
  [8] de_DE.iso885915
  [9] de_DE.utf8
  [ ] (free form)
</pre>

<p>
With <c>eselect locale set &lt;value&gt;</c> the correct locale can be set:
</p>

<pre caption="Setting the LANG variable">
# <i>eselect locale set 9</i>
</pre>

<p>
Manually, this can still be accomplished through the
<path>/etc/env.d/02locale</path> file:
</p>

<pre caption="Setting the default system locale in /etc/env.d/02locale">
LANG="de_DE.UTF-8"
LC_COLLATE="C"
</pre>

<p>
Don't forget to reload your environment:
</p>

<pre caption="Reload shell environment">
# <i>env-update &amp;&amp; source /etc/profile</i>
</pre>

<p>
We made a full <uri link="https://wiki.gentoo.org/wiki/Localization/HOWTO">Localization
Guide</uri> to help you through this process. You can also read the detailed
<uri link="https://wiki.gentoo.org/wiki/UTF-8">UTF-8 article</uri> for very specific
informations to enable UTF-8 on your system.
</p>

<p test="not(func:keyval('arch')='PPC64')">
Please continue with <uri link="?part=1&amp;chap=9">Installing Necessary System
Tools</uri>.
</p>

</body>
</subsection>
<subsection test="func:keyval('arch')='PPC64'">
<title>Configuring the Console</title>
<body>

<p>
If you are using a virtual console, you must uncomment the appropriate line in
<path>/etc/inittab</path> for the virtual console to spawn a login prompt.
</p>

<pre caption="Enabling hvc or hvsi support in /etc/inittab">
hvc0:12345:respawn:/sbin/agetty -L 9600 hvc0
hvsi:12345:respawn:/sbin/agetty -L 19200 hvsi0
</pre>

<p>
You should also take this time to verify that the appropriate console is 
listed in <path>/etc/securetty</path>.
</p>

<p>
You may now continue with <uri link="?part=1&amp;chap=9">Installing Necessary 
System Tools</uri>.
</p>

</body>
</subsection>
</section>
</sections>