System information

10 Sharing and maintaining SLES 10 SP2 Linux under z/VM
/dev
This directory highlights one important characteristic of the Linux file system - almost
everything is a file or a directory. If you look at this directory and you should see dasda1,
dasda2 etc, which represent the various partitions on the disk drive of the system. The entries
beginning with sda* are SCSI devices. Each logical minidisk would be represented as dasda
for the first, dasdb for the second, etc...
/etc
The FHS states:
“This is the nerve center of your system, it contains all system related configuration files
(or in subdirectories). A “configuration file” is defined as a local file used to control the
operation of a program; it must be static and cannot be an executable binary. For this
reason, it's a good idea to backup this directory regularly. Normally, no binaries should be
or are located here.”
/home
The LSB states that:
“Linux is a multi-user environment so each user is also assigned a specific directory which
is accessible only to them and the system administrator. These are the user home
directories, which can be found under /home/<username>. This directory also contains the
user specific settings for programs like IRC, X etc.”
The FHS states that:
“/home is a fairly standard concept, but it is clearly a site-specific file system. Different
people prefer to place user accounts in a variety of places. This section describes only a
suggested placement for user home directories; nevertheless we recommend that all
FHS-compliant distributions use this as the default location for home directories. On small
systems, each user's directory is typically one of the many subdirectories of /home such
as /home/smith, /home/torvalds, /home/operator, etc. On large systems (especially when
the /home directories are shared amongst many hosts using NFS) it is useful to subdivide
user home directories. Subdivision may be accomplished by using subdirectories such as
/home/staff, /home/guests, /home/students, etc.
The setup will differ from host to host. Therefore, no program should rely on this location.
If you want to find out a user's home directory, you should use the getpwent(3) library
function rather than relying on /etc/passwd because user information may be stored
remotely using systems such as NIS.
User specific configuration files for applications are stored in the user's home directory in a
file that starts with the '.' character (a “dot file”). If an application needs to create more than
one dot file then they should be placed in a subdirectory with a name starting with a '.'
character, (a “dot directory”). In this case the configuration files should not start with the '.'
character.
It is recommended that apart from autosave and lock files programs should refrain from
creating non dot files or directories in a home directory without user intervention.”
In this paper, /home/ is not addressed in detail, though there is a short discussion of using
automount, NFS and LDAP in 1.9.2, “Implementing /home/ with automount, NFS and LDAP”
on page 65.
/lib
The LSB states that: