Man page of LIMITS.CONF
Section: Linux-PAM Manual (5)
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limits.conf - configuration file for the pam_limits module
The syntax of the lines is as follows:
The fields listed above should be filled as follows:
•a groupname, with
syntax. This should not be confused with netgroups.
*, for default entry.
%, for maxlogins limit only, can also be used with
group and wildcard limits are not applied to the root user. To set a limit for the root user, this field must contain the literal username
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.
resource limits. These limits are ones that the user can move up or down within the permitted range by any pre-existing
limits. The values specified with this token can be thought of as
values, for normal system usage.
for enforcing both
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. .
limits the core file size (KB)
maximum data size (KB)
maximum filesize (KB)
maximum locked-in-memory address space (KB)
maximum number of open files
maximum resident set size (KB)
maximum stack size (KB)
maximum CPU time (minutes)
maximum number of processes
address space limit (KB)
maximum number of logins for this user except for this with
maximum number of logins on system
the priority to run user process with (negative values boost process priority)
maximum locked files (Linux 2.4 and higher)
maximum number of pending signals (Linux 2.6 and higher)
maximum memory used by POSIX message queues (bytes) (Linux 2.6 and higher)
maximum nice priority allowed to raise to (Linux 2.6.12 and higher) values: [-20,19]
maximum realtime priority allowed for non-privileged processes (Linux 2.6.12 and higher)
the directory to chroot the user to
In general, individual limits have priority over group limits, so if you impose no limits for
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.
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
These are some example lines which might be specified in
* soft core 0
root hard core 100000
* hard rss 10000
@student hard nproc 20
@faculty soft nproc 20
@faculty hard nproc 50
ftp hard nproc 0
@student - maxlogins 4
pam_limits was initially written by Cristian Gafton <email@example.com>
- SEE ALSO
This document was created by
using the manual pages.
Time: 04:16:05 GMT, September 24, 2010