The Home Directory

The home directory is the portion of a file system allocated to a user for storing private files. The amount of space you allocate for home directories depends on the kinds of files the user creates and the type of work performed. An entire file system is usually allocated specifically for home directories, and the users all share this space. The system administrator needs to monitor user home directories so that one user does not use more than his fair share of space. Disk quotas are used to control the amount of disk space a user can occupy. (These are discussed in Chapter 14, “Managing File Systems.”)

A home directory can be located either on the user’s local system or on a remote file server. Although any directory name can be used, the home directory in either case is, by convention, /export/home/<username>. When you put the home directory in /export/home, it is available across the network in case the user logs in from several different stations. For a large site, you should store home directories on a server.

Regardless of where their home directories are located, users usually access them through a mount point named /home/<username>. When Autofs is used to mount home directories, you are not permitted to create any directories under the /home mount point on any system. The system recognizes the special status of /home when Autofs is active. For more information about Autofs and automounting home directories, see Chapter 22, “The NFS Environment.”

To access the home directory anywhere on the network, you should always refer to it as $HOME, not as /export/home/<username>. The latter is machine specific and should be discouraged. In addition, any symbolic links created in a user’s home directory should use relative paths (for example, ../../../x/y/x) so that the links will be valid no matter where the home directory is mounted. The location of user home directories might change. By not using machine-specific names, you maintain consistency and reduce system administration.