Linux allows you to control how many opened file descriptor an user can have at any one time.

System-Wide Settings[edit]

To show the number of files opened on a system, run:

# cat /proc/sys/fs/file-nr
1536	0	793120

The fields are:

  1. Current number of opened files
  2. Number of free allocated file descriptors
  3. Maximum number of file descriptors for the whole system

You may change this value by:

# cat <new value> > /proc/sys/fs/file-nr
## Edit <code>/etc/sysctl.conf</code> so that there is a line
## fs.file-max = <new value>

Per-User Settings[edit]

You can see the limits set by running ulimit on the bash shell.

# ulimit -n

You can also see the per-user limits defined in /etc/security/limits.conf:

# cat /etc/security/limits.conf

See Also[edit]