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