limits.conf
TLDR
Set maximum open files for user
$ [username] hard nofile [65535]
Set memory limit$ [username] hard as [4194304]
Set for all users$ * soft nproc [1024]
Set for group$ @[groupname] hard maxlogins [10]
SYNOPSIS
/etc/security/limits.conf
DESCRIPTION
limits.conf is a PAM configuration file that sets resource limits for users and groups. Limits are enforced when users log in through PAM-enabled services.
The format is: domain type item value. Domain can be username, @groupname, or * for all users.
PARAMETERS
hard
Hard limit (maximum value).soft
Soft limit (default value).nofile
Maximum open files.nproc
Maximum processes.as
Address space limit.maxlogins
Maximum logins.memlock
Maximum locked memory.stack
Maximum stack size.
EXAMPLE CONFIG
$ # /etc/security/limits.conf
* soft nofile 4096
* hard nofile 65535
@developers soft nproc 2048
root hard nproc unlimited
* soft nofile 4096
* hard nofile 65535
@developers soft nproc 2048
root hard nproc unlimited
CAVEATS
Requires pam_limits module. Changes apply at next login. Systemd services may need LimitNOFILE in unit files. Check with ulimit -a.
SEE ALSO
ulimit(1), pam(8), pam_limits(8), sysctl(8)
