addmntent - Linux


addmntent manages the file /etc/mtab which contains information about mounted filesystems. It is used to add or remove entries from this file, enabling administrators to manually control the mounting of filesystems.


addmntent [-u] [-f <path_to_file>] <fstype> <mntpoint> <device> <opts>


  • -u: Update an existing entry in /etc/mtab instead of adding a new one.
  • -f <path_to_file>: Specify an alternative file to add entries to instead of /etc/mtab.


Adding an Entry

addmntent ext3 /mnt /dev/sda1 rw

Updating an Entry

addmntent -u ext3 /mnt /dev/sda1 rw,noatime

Common Issues

  • Permission Denied: Ensure you have root privileges to update /etc/mtab.
  • Invalid Entry: Verify that the provided mountpoint, device, and options are valid.


addmntent can be used with other commands like:

  • mount: To mount a filesystem based on the entry added to /etc/mtab.
  • umount: To unmount a filesystem based on the entry removed from /etc/mtab.

Related Commands

  • mount
  • umount
  • fstab