The default settings are very low for high performance servers and should be increased.

To change the file descriptor setting, edit the kernel parameter file /etc/sysctl.conf.

Add line fs.file-max=[new value] to it.

To change the ulimit setting, edit the file /etc/security/limits.conf and set the hard and soft limits.

How do I permanently set Ulimit in Linux?

Procedure

• To set or verify the ulimit values on AIX: Log in as the root user. Run the following commands: chuser nofiles=32768 nofiles_hard=65536 admin_user_ID.
• To set or verify the ulimit values on Linux: Log in as the root user. Edit the /etc/security/limits.conf file and specify the following values:

What is Ulimit command in Linux?

Ulimit Command. The shell contains a built in command called “Ulimit” which allows you to display and set resource limits for users. The systems resources are defined in a file called “/etc/security/limits.conf”. Ulimit can then be used to view these settings.