In the /etc/auto.master configuration file, each map entry specifies a mount point and a map file that contains definitions of the remote file systems that can be mounted, for example:

/-          /etc/auto.direct
/misc       /etc/auto.misc
/net        -hosts

The previous example shows the following types of map entries:

• /-: direct map entry. Direct map entries always specify /- as the mount point.

• /misc: indirect map entry.

• /net: host map entry. Host maps always specify the keyword -hosts instead of a map file.

A direct map contains definitions of directories that are automounted at the specified absolute path. In the example, the auto.direct map file might contain an entry similar to the following:

/usr/man   -fstype=nfs,ro,soft             host01:/usr/man

This entry is a directive to do the following:

• Mount the file system /usr/man that's exported by host01 by specifying the ro and soft options.

• Create the /usr/man mount point if it doesn't already exist. If the mount point exists , the mounted file system hides any existing files that it contains.

Because the default file system type is NFS, the previous example can be shortened to read as follows:

/usr/man   -ro,soft                        host01:/usr/man

An indirect map contains definitions of directories or keys that are automounted relative to the mount point (/misc) that's specified in the /etc/auto.master file. For example, the /etc/auto.misc map file might contain entries similar to the following:

xyz       -ro,soft                         host01:/xyz
cd        -fstype=iso9600,ro,nosuid,nodev        :/dev/cdrom
abc       -fstype=ext3                           :/dev/hda1
fenetres  -fstype=cifs,credentials=credfile      ://fenetres/c

Note that the /misc directory must already exist; however, the automounter creates a mount point for the keys xyz, cd , and so on, if they don't already exist, and then removes them when it unmounts the file system.

For example, using the ls /misc/xyz command causes the automounter to the mount the /xyz directory, exported by host01 as /misc/xyz.

The cd and abc entries mount the following local file systems: an ISO image from the CD-ROM drive on /misc/cd and an ext3 file system from /dev/hda1 on /misc/abc. The fenetres entry mounts a Samba share as /misc/fenetres.

If a host map entry exists, and a command references an NFS server that's relative to the mount point (/net) by name, the automounter mounts all the directories that the server exports within a subdirectory of the mount point named for the server. For example, the cd /net/host03 command causes the automounter to mount all exports from host03 under the /net/host03 directory. By default, the automounter uses the nosuid,nodev,intr mount options unless you override the options in the host map entry, as follows:

/net        -hosts    -suid,dev,nointr

For more information about NFS administration, see the Using NFS in Oracle Linux chapter in Oracle Linux 8: Managing Shared File Systems Oracle Linux 9: Managing Shared File Systems. See also the hosts.master(5) and auto.master(5) manual pages.

1. Install the autofs package and any other packages that are required to support remote file systems:

   sudo dnf install autofs

2. Edit the /etc/auto.master configuration file to define map entries that are appropriate to the file systems.

   See About the Automounter Configuration File for reference.

3. Start the autofs service, and configure the service to start following a system reboot:

   sudo systemctl start autofs
   sudo systemctl enable autofs

You can configure various settings for autofs in the /etc/sysconfig/autofs file, including the idle timeout value after which a file system is automatically unmounted.

If you change the /etc/auto.master or /etc/sysconfig/autofs file, restart the autofs service to reread these files:

sudo systemctl restart autofs

For more information, see the automount(8) and autofs(5) manual pages.