How to set ulimit values-蒲公英云

How to set ulimit values

以你之姓@ 2024-02-20 11:35 180阅读 0赞

Environment

Red Hat Enterprise Linux (RHEL)

Issue

How to set ulimit values

Resolution

Settings in /etc/security/limits.conf take the following form:

Raw

# vi /etc/security/limits.conf
#<domain>        <type>  <item>  <value>
*               -       core             <value>
*               -       data             <value>
*               -       priority         <value>
*               -       fsize            <value>
*               soft    sigpending       <value> eg:57344
*               hard    sigpending       <value> eg:57444
*               -       memlock          <value>
*               -       nofile           <value> eg:1024
*               -       msgqueue         <value> eg:819200
*               -       locks            <value>
*               soft    core             <value>
*               hard    nofile           <value>
@<group>        hard    nproc            <value>
<user>          soft    nproc            <value>
%<group>        hard    nproc            <value>
<user>          hard    nproc            <value>
@<group>        -       maxlogins        <value>
<user>          hard    cpu              <value>
<user>          soft    cpu              <value>
<user>          hard    locks            <value>

<domain> can be:
- a user name
- a group name, with @group syntax
- the wildcard *, for default entry
- the wildcard %, can be also used with %group syntax, for maxlogin limit
<type> can have two values:
- soft for enforcing the soft limits
- hard for enforcing hard limits
- - for enforcing soft as well as hard limits
<item> can be one of the following:
- core - limits the core file size (KB)
- data - max data size (KB)
- fsize - maximum filesize (KB)
- memlock - max locked-in-memory address space (KB)
- nofile - max number of open files
- rss - max resident set size (KB)
- stack - max stack size (KB)
- cpu - max CPU time (MIN)
- nproc - max number of processes (see note below)
- as - address space limit (KB)
- maxlogins - max number of logins for this user
- maxsyslogins - max number of logins on the system
- priority - the priority to run user process with
- locks - max number of file locks the user can hold
- sigpending - max number of pending signals
- msgqueue - max memory used by POSIX message queues (bytes)
- nice - max nice priority allowed to raise to values: [-20, 19]
- rtprio - max realtime priority

Exit and re-login from the terminal for the change to take effect.
More details can be found from below command:

Raw
```
# man limits.conf
```
Note that the nproc setting can no longer be set in limits.conf. Please use /etc/security/limits.d/90-nproc.conf instead. Setting nproc in /etc/security/limits.conf has no effect in Red Hat Enterprise Linux.

Diagnostic Steps

To improve performance, we can safely set the limit of processes for the super-user root to be unlimited. Edit the .bashrc file and add the following line:

Raw
```
# vi /root/.bashrc
ulimit -u unlimited
```
Exit and re-login from the terminal for the change to take effect.
Can also run ulimit -u unlimited at the command prompt instead of adding it to the file /root/.bashrc.