About Autofs

File systems that are shared through the NFS service can be mounted by using automatic mounting. Autofs, a client-side service, is a file system structure that provides automatic mounting. The autofs file system is initialized by automount, which is run automatically when a system is booted. The automount daemon, automountd, runs continuously, mounting and unmounting remote directories as necessary.

Whenever a user on a client computer that is running automountd tries to access a remote file or directory, the daemon mounts the file system to which that file or directory belongs. This remote file system remains mounted for as long as it is needed. If the remote file system is not accessed for a certain period of time, it is automatically unmounted.

Mounting need not be done at boot time, and the user no longer has to know the superuser password to mount a directory. Users do not need to use the mount and umount commands. The autofs service mounts and unmounts file systems as required without any intervention by the user.

Mounting some file hierarchies with automountd does not exclude the possibility of mounting other hierarchies with mount. A diskless computer must mount / (root), /usr, and /usr/kvm through the mount command and the /etc/vfstab file.

"Autofs Administration Task Overview" and "How Autofs Works" give more specific information about the autofs service.