LIMITS.CONF(5)

NAME

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:

<domain>: o a username; o a groupname, with @group syntax. This should not be confused
with netgroups.; o the wildcard *, for default entry.; o the wildcard %, for maxlogins limit only, can also be used with
%group syntax.

NOTE: 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 root.; <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-existing hard limits. The values specified with this token can be thought of as default values, for normal system usage.

These are some example lines which might be specified in /etc/security/limits.conf.: * 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 <gafton@redhat.com>