Chapter 7. Understanding the Automounter

The automounter works with the NFS (network file system) to automatically mount and unmount directories from other systems on the network as they are needed. The automounter supplements the virtual file system table (/etc/vfstab) and manual mount and unmount activities with an automatic, on-demand facility. When the user types a command that accesses a remote file or directory, the automounter consults a series of maps—described in detail later in this chapter—to determine which directories to mount, which system to mount them from, which mount parameters to use, and where to mount them on the user's local system. The directory remains mounted as long as it is in use. When the user exits from the file or the directory, the resource is automatically unmounted if it has not been accessed for 5 minutes.

Although you could administer the automounter by editing local automount maps in the /etc directory, Sun recommends that you use the NIS, NIS+, or LDAP nameservice with the automounter. Using a nameservice creates a consistent global namespace for your users and a centralized control model for your administrators, and it provides a consistent automounter configuration throughout the domain.

This chapter describes some automount terminology, the automount maps and mount points, and the way in which automounting works. It also provides some example maps and suggests policies you can use to implement automounting in your network environment. (Chapter 8, “Setting Up the Automounter,” discusses how to create and edit automount maps.)