NFS Services Administrator's Guide (B.11.31.03) August 2008

Following sections describe the different components of AutoFS that work together to
automatically mount and unmount filesystems, in detail.
AutoFS Filesystem
The AutoFS filesystem is a virtual filesystem that provides a directory structure to
enable automatic mounting of filesystems. It includes autofskd, a kernel-based process
that periodically cleans up 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 3-1 illustrates how the AutoFS components interact.
Figure 3-1 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.
68 Configuring and Administering AutoFS