contains files to which the system writes data during the course of its operation
files whose content is expected to continually change during normal operation of the system—such as logs, spool files, and temporary e-mail files
is specific for each system, i.e., not shared over the network with other computers
Subdirectories
directory
description
/var/cache
contains cached data from application programs
such data are locally generated as a result of time-consuming I/O or calculation
the application must be able to regenerate or restore the data
the cached files can be deleted without loss of data
/var/cache/man
A cache for man pages that are formatted on demand. The source for manual pages is usually stored in /usr/share/man/man?/ (where ? is the manual section. See the manual page for man in section 7); some manual pages might come with a pre-formatted version, which might be stored in /usr/share/man/cat* . Other manual pages need to be formatted when they are first viewed; the formatted version is then stored in /var/cache/man so that the next person to view the same page won’t have to wait for it to be formatted
/var/lib
contains dynamic data libraries and files
state information
contains files that change while the system is running normally
persistent data modified by programs as they run, e.g., databases, packaging system metadata, etc.
/var/games
contains any variable data belonging to games in usr should be placed here
this is in case /usr is mounted read only
/var/log
contains various log files from various programs:
login (/var/log/wtmp, which logs all logins and logouts into the system)
syslog (/var/log/messages, where all kernel and system program message are usually stored)
files in /var/log can often grow indefinitely, and may require cleaning at regular intervals
/var/mail
mailbox files
this is the FHS approved location for user mailbox files
depending on how far your distribution has gone towards FHS compliance, these files may still be held in /var/spool/mail
/var/opt
variable data from add-on packages that are stored in /opt
/var/run
run-time variable data
contains system information data describing the system since it was booted
contains PIDs and other system information that is valid until the system is rebooted
files that contain information about the system that is valid until the system is next booted. For example, /var/run/utmp contains information about people currently logged in
in FHS 3.0, /var/run is replaced by /run; a system should either continue to provide a /var/run directory, or provide a symbolic link from /var/run to /run, for backwards compatibility
/var/spool
contains mail, news, and printer queues
spool for tasks waiting to be processed, e.g., print queues and outgoing mail queue
directories for news, printer queues, and other queued work. Each different spool has its own subdirectory below /var/spool, e.g., the news spool is in /var/spool/news . Note that some installations which are not fully compliant with the latest version of the FHS may have user mailboxes under /var/spool/mail
/var/spool/mail
deprecated location for users’ mailboxes, replaced by /var/mail
/var/tmp
temporary files to be preserved between reboots
/var/local
variable data for programs that are installed in /usr/local (i.e., programs that have been installed by the system administrator)
Note that even locally installed programs should use the other /var directories if they are appropriate, e.g., /var/lock
/var/lock
lock files
files keeping track of resources currently in use
contains lock files created by programs to indicate that they are using a particular file or device
many programs follow a convention to create a lock file in /var/lock to indicate that they are using a particular device or file. Other programs will notice the lock file and won’t attempt to use the device or file