LIMITS.CONF(5) Linux-PAM Manual LIMITS.CONF(5)NAMElimits.conf - configuration file for the pam_limits module
DESCRIPTION
The syntax of the lines is as follows:
<domain><type><item><value>
The fields listed above should be filled as follows:
<domain>
· a username
· a groupname, with @group syntax. This should not be confused
with netgroups.
· the wildcard *, for default entry.
· the wildcard %, for maxlogins limit only, can also be used
with %group syntax.
<type>
hard for enforcing hard resource limits. These limits are set
by the superuser and enforced by the Kernel. The user
cannot raise his requirement of system resources above
such values.
soft for enforcing soft resource limits. These limits are ones
that the user can move up or down within the permitted
range by any pre-exisiting hard limits. The values
specified with this token can be thought of as default
values, for normal system usage.
- for enforcing both soft and hard resource limits
together.
Note, if you specify a type of '-' but neglect to supply
the item and value fields then the module will never
enforce any limits on the specified user/group etc. .
<item>
core limits the core file size (KB)
data maximum data size (KB)
fsize maximum filesize (KB)
memlock
maximum locked-in-memory address space (KB)
nofile maximum number of open files
rss maximum resident set size (KB) (Ignored in Linux 2.4.30
and higher)
stack maximum stack size (KB)
cpu maximum CPU time (minutes)
nproc maximum number of processes
as address space limit
maxlogins
maximum number of logins for this user
maxsyslogins
maximum number of logins on system
priority
the priority to run user process with (negative values
boost process priority)
locks maximum locked files (Linux 2.4 and higher)
sigpending
maximum number of pending signals (Linux 2.6 and higher)
msqqueue
maximum memory used by POSIX message queues (bytes)
(Linux 2.6 and higher)
nice maximum nice priority allowed to raise to (Linux 2.6.12
and higher)
rtprio maximum realtime priority allowed for non-privileged
processes (Linux 2.6.12 and higher)
In general, individual limits have priority over group limits, so if
you impose no limits for admin group, but one of the members in this
group have a limits line, the user will have its limits set according
to this line.
Also, please note that all limit settings are set per login. They are
not global, nor are they permanent; existing only for the duration of
the session.
In the limits configuration file, the '#' character introduces a
comment - after which the rest of the line is ignored.
The pam_limits module does its best to report configuration problems
found in its configuration file via syslog(3).
EXAMPLES
These are some example lines which might be specified in
/etc/security/limits.conf.
* soft core 0
* hard rss 10000
@student hard nproc 20
@faculty soft nproc 20
@faculty hard nproc 50
ftp hard nproc 0
@student - maxlogins 4
SEE ALSOpam_limits(8), pam.d(5), pam(8)AUTHOR
pam_limits was initially written by Cristian Gafton <gafton@redhat.com>
Linux-PAM Manual 01/09/2013 LIMITS.CONF(5)
