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<?xml version="1.0" encoding='UTF-8'?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd">
<refentry id="limits.conf">
<refmeta>
<refentrytitle>limits.conf</refentrytitle>
<manvolnum>5</manvolnum>
<refmiscinfo class="sectdesc">Linux-PAM Manual</refmiscinfo>
</refmeta>
<refnamediv>
<refname>limits.conf</refname>
<refpurpose>configuration file for the pam_limits module</refpurpose>
</refnamediv>
<refsect1 id='limits.conf-description'>
<title>DESCRIPTION</title>
<para>
The syntax of the lines is as follows:
</para>
<para>
<replaceable><domain></replaceable> <replaceable><type></replaceable>
<replaceable><item></replaceable> <replaceable><value></replaceable>
</para>
<para>
The fields listed above should be filled as follows:
</para>
<variablelist>
<varlistentry>
<term>
<option><domain></option>
</term>
<listitem>
<itemizedlist>
<listitem>
<para>
a username
</para>
</listitem>
<listitem>
<para>
a groupname, with <emphasis remap='B'>@group</emphasis> syntax.
This should not be confused with netgroups.
</para>
</listitem>
<listitem>
<para>
the wildcard <emphasis remap='B'>*</emphasis>, for default entry.
</para>
</listitem>
<listitem>
<para>
the wildcard <emphasis remap='B'>%</emphasis>, for maxlogins limit only,
can also be used with <emphasis remap='b'>%group</emphasis> syntax.
</para>
</listitem>
</itemizedlist>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option><type></option>
</term>
<listitem>
<variablelist>
<varlistentry>
<term><option>hard</option></term>
<listitem>
<para>
for enforcing <emphasis remap='B'>hard</emphasis> 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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>soft</option></term>
<listitem>
<para>
for enforcing <emphasis remap='B'>soft</emphasis> resource limits.
These limits are ones that the user can move up or down within the
permitted range by any pre-exisiting <emphasis remap='B'>hard</emphasis>
limits. The values specified with this token can be thought of as
<emphasis>default</emphasis> values, for normal system usage.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-</option></term>
<listitem>
<para>
for enforcing both <emphasis remap='B'>soft</emphasis> and
<emphasis remap='B'>hard</emphasis> resource limits together.
</para>
<para>
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. .
</para>
</listitem>
</varlistentry>
</variablelist>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option><item></option>
</term>
<listitem>
<variablelist>
<varlistentry>
<term><option>core</option></term>
<listitem>
<para>limits the core file size (KB)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>data</option></term>
<listitem>
<para>maximum data size (KB)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>fsize</option></term>
<listitem>
<para>maximum filesize (KB)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>memlock</option></term>
<listitem>
<para>maximum locked-in-memory address space (KB)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>nofile</option></term>
<listitem>
<para>maximum number of open files</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>rss</option></term>
<listitem>
<para>maximum resident set size (KB)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>stack</option></term>
<listitem>
<para>maximum stack size (KB)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>cpu</option></term>
<listitem>
<para>maximum CPU time (minutes)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>nproc</option></term>
<listitem>
<para>maximum number of processes</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>as</option></term>
<listitem>
<para>address space limit (KB)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>maxlogins</option></term>
<listitem>
<para>maximum number of logins for this user</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>maxsyslogins</option></term>
<listitem>
<para>maximum number of logins on system</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>priority</option></term>
<listitem>
<para>the priority to run user process with (negative
values boost process priority)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>locks</option></term>
<listitem>
<para>maximum locked files (Linux 2.4 and higher)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>sigpending</option></term>
<listitem>
<para>maximum number of pending signals (Linux 2.6 and higher)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>msqqueue</option></term>
<listitem>
<para>maximum memory used by POSIX message queues (bytes)
(Linux 2.6 and higher)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>nice</option></term>
<listitem>
<para>maximum nice priority allowed to raise to (Linux 2.6.12 and higher)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>rtprio</option></term>
<listitem>
<para>maximum realtime priority allowed for non-privileged processes
(Linux 2.6.12 and higher)</para>
</listitem>
</varlistentry>
</variablelist>
</listitem>
</varlistentry>
</variablelist>
<para>
In general, individual limits have priority over group limits, so if
you impose no limits for <emphasis>admin</emphasis> group, but one of
the members in this group have a limits line, the user will have its
limits set according to this line.
</para>
<para>
Also, please note that all limit settings are set
<emphasis>per login</emphasis>. They are not global, nor are they
permanent; existing only for the duration of the session.
</para>
<para>
In the <emphasis>limits</emphasis> configuration file, the
'<emphasis remap='B'>#</emphasis>' character introduces a comment
- after which the rest of the line is ignored.
</para>
<para>
The pam_limits module does its best to report configuration problems
found in its configuration file via <citerefentry>
<refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para>
</refsect1>
<refsect1 id="limits.conf-examples">
<title>EXAMPLES</title>
<para>
These are some example lines which might be specified in
<filename>/etc/security/limits.conf</filename>.
</para>
<programlisting>
* 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
</programlisting>
</refsect1>
<refsect1 id="limits.conf-see_also">
<title>SEE ALSO</title>
<para>
<citerefentry><refentrytitle>pam_limits</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>pam.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>
</refsect1>
<refsect1 id="limits.conf-author">
<title>AUTHOR</title>
<para>
pam_limits was initially written by Cristian Gafton <gafton@redhat.com>
</para>
</refsect1>
</refentry>
|
