Handbook:Parts/Installation/System

About fstab
Under Linux, all partitions used by the system must be listed in. 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.)

Creating the fstab file
The file uses a table-like syntax. Every line consists of six fields, separated by whitespace (space(s), tabs or a mixture). Each field has its own meaning:


 * 1) The first field shows the partition described (the path to the device file)
 * 2) The second field shows the mount point at which the partition should be mounted
 * 3) The third field shows the filesystem used by the partition
 * 4) The fourth field shows the mount options used by   when it wants to mount the partition. As every filesystem has its own mount options, users are encouraged to read the mount man page  for a full listing. Multiple mount options are comma-separated.
 * 5) The fifth field is used by dump to determine if the partition needs to be dumped or not. This can generally be left as 0 (zero).
 * 6) The sixth field is used by fsck to determine the order in which filesystems should be checked if the system wasn't shut down properly. The root filesystem should have 1 while the rest should have 2 (or 0 if a filesystem check isn't necessary).

In the remainder of the text, we use the default block device files as partition. Users can also opt to use the symbolic links in the or  locations. 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 the system). However, unless someone intends to fiddle with the disk ordering, one can continue with the default block device files safely.

Let us take a look at how to write down the options for the partition. This is just an example, and should be modified according to the partitioning decisions made earlier in the installation.

In our partitioning example,  is usually the  partition, with ext2 as filesystem. It needs to be checked during boot, so we would write down:

Some users don't want their partition to be mounted automatically to improve their system's security. Those people should substitute defaults with noauto. This does mean that those users will need to manually mount this partition every time they want to use it.

Add the rules that match the previously decided partitioning scheme and append rules for devices such as CD-ROM drive(s), and of course, if other partitions or drives are used, for those too.

Below is a more elaborate example of an file:

When auto is used in the third field, it makes the  command guess what the filesystem would be. This is recommended for removable media as they can be created with one of many filesystems. The user option in the fourth field makes it possible for non-root users to mount the CD.

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

Double-check the file, save and quit to continue.

Host and domain information
One of the choices the user has to make is name his/her PC. This seems to be quite easy, but lots of users are having difficulties finding the appropriate name for their Linux-pc. To speed things up, know that the decision is not final - it can be changed afterwards. In the examples below, the hostname tux is used within the domain homenetwork.

Second, if a domainname is needed, set it in. This is only necessary if the ISP or network administrator says so, or if the network has a DNS server but not a DHCP server. Don't worry about DNS or domainnames if the system uses DHCP for dynamic IP address allocation and network configuration.

If a NIS domain is needed (users that do not know this will not need one), define that one too:

Configuring the network
During the Gentoo Linux installation, networking was already configured. However, that was for the installation CD itself and not for the installed environment. Right now, the network configuration is made for the installed Gentoo Linux system.

All networking information is gathered in. It uses a straightforward yet perhaps not intuitive syntax. But don't fear, everything is explained below. A fully commented example that covers many different configurations is available in.

First install :

DHCP is used by default. For DHCP to work, a DHCP client needs to be installed. This is described later in Installing Necessary System Tools.

If the network connection needs to be configured because of specific DHCP options or because DHCP is not used at all, then open :

Set both  and   to enter IP address information and routing information:

To use DHCP, define :

Please read for a list of all available options. Be sure to also read up on the DHCP client man page if specific DHCP options need to be set.

If the system has several network interfaces, then repeat the above steps for,  , etc.

Now save the configuration and exit to continue.

Automatically start networking at boot
To have the network interfaces activated at boot, they need to be added to the default runlevel.

If the system has several network interfaces, then the appropriate files need to be created just like we did with.

If after booting the system we find out that the assumption about the network interface name (which is currently documented as ) was wrong, then execute the following steps to rectify this:


 * 1) Update the  file with the correct interface name (like   instead of  )
 * 2) Create new symbolic link (like )
 * 3) Remove the old symbolic link
 * 4) Add the new one to the default runlevel
 * 5) Remove the old one using

The hosts file
Next inform Linux about the network environment. This is defined in and helps in resolving host names to IP addresses for hosts that aren't resolved by the nameserver.

Save and exit the editor to continue.

Optional: Get PCMCIA working
PCMCIA users should now install the package.

Root password
Set the root password using the  command.

The root Linux account is an all-powerful account, so pick a strong password. Later an additional regular user account will be created for daily operations.

Init and boot configuration
Gentoo (at least when using OpenRC) uses to configure the services, startup, and shutdown of a system. Open up and enjoy all the comments in the file. Review the settings and change where needed.

Next, open to handle keyboard configuration. Edit it to configure and select the right keyboard.

Take special care with the  variable. If the wrong keymap is selected, then weird results will come up when typing on the keyboard.

Finally, edit to set the clock options. Edit it according to personal preference.

If the hardware clock is not using UTC, then it is necessary to set  in the file. Otherwise the system might show clock skew behavior.