ulimit configuration

This note was created on 2019-04-19
This note was last edited on 2023-04-19

=== Types of limits ===
- Soft limit (All users can change soft limits, up to max set by the hard limits. Pass the -S option to the ulimit).
- Hard limit (Only root users allowed to change esource hard limits. Pass the -H option to the ulimit).

=== Check global limits ===
Show soft limit:
# ulimit -Sa
Show hard limit:
# ulimit -Ha

=== Check limits for process ===
1. Find PID:
   $ ps aux | grep *process name*
2. Get limits:
   $ cat /proc/530/limits

=== Change limits ===
For current session:
# ulimit -n 65535

Permanent:
1. Add following to "/etc/security/limits.conf":
   ~~~
   *      soft     nproc          65535
   *      hard     nproc          65535
   *      soft     nofile         65535
   *      hard     nofile         65535
   root   soft     nproc          65535
   root   hard     nproc          65535
   root   soft     nofile         65535
   root   hard     nofile         65535
   ~~~
2. Reboot and check result:
   $ ulimit -n