NFS Services Administrator's Guide (B1031-90072, March 2011)

mounts. The filesystem interacts with the automount command and the automountd daemon to
mount filesystems automatically.
The automount Command
This command installs the AutoFS mount-points, and associates an automount map with each
mount-point. The AutoFS filesystem monitors attempts to access directories within it and notifies the
automountd daemon. The daemon locates a filesystem using the map, and then mounts this
filesystem at the point of reference within the AutoFS filesystem. The automount map specifies the
location of all the AutoFS mount-points.
NOTE: You must run the automount command whenever the master map or the direct maps
are updated.
The automountd Daemon
The automountd daemon is a stateless, multi-threaded daemon that mounts or unmounts directories
and filesystems by accepting Remote Procedure Calls (RPC) requests.
Figure 6 illustrates how the AutoFS components interact.
Figure 6 Interaction between AutoFS Components
The automount command reads the AutoFS master map to create the initial set of AutoFS
mount-points in the internal mount table, /etc/mnttab. The automounted filesystems are not
mounted automatically at startup. The automounted filesystems are points under which the filesystems
are mounted when the clients request access to them.
When AutoFS receives a request to mount a filesystem, it calls the automountd daemon, which
mounts the requested filesystem. AutoFS mounts the filesystems at the configured mount-points.
The automountd daemon is independent of the automount command. This separation enables
you to add, delete, or modify the AutoFS map information, without stopping and restarting the
automountd daemon. You can modify the set of mount-points by modifying the AutoFS maps and
by running the automount command to read them and update the mount table.
If an automounted filesystem remains idle for a specified period of time (the default is 10 minutes),
AutoFS unmounts it. To change the duration, in seconds, for which a file system is to remain mounted
48 Configuring and Administering AutoFS