NFS Services Administrator's Guide (B.11.31.02) January 2008

Table 3-4 Direct Versus Indirect AutoFS Map Types (continued)
Indirect MapDirect Map
Advantage: If you modify an indirect map, AutoFS will
view the changes the next time it mounts the directory.
You need not force AutoFS to reread its maps.
Disadvantage: If you add or remove mounts in a direct
map, or if you change the local mount-point for an
existing mount in a direct map, you must force AutoFS
to reread its maps.
Advantage: When automount reads an indirect map, it
creates only one entry for the entire map in the internal
mount table, /etc/mnttab. Additional entries are
created when the directories are actually mounted. The
mount table takes up no more space than necessary,
because only mounted directories appear in it.
Disadvantage: When automount reads a direct map, it
creates an entry for each automounted directory in the
internal mount table, /etc/mnttab. This can cause the
mount table to become very large.
Configuring AutoFS Direct and Indirect Mounts
A direct map is an automount mount-point. It creates a direct association between a mount-point
on the client and a directory on the server. Direct maps have the absolute path name. The
automounts configured in a direct map can be mounted in various places in the local filesystem;
they need not be located under the same parent directory.
An indirect map uses the key to establish a connection between a mount-point on the client and
a directory on the server. Indirect maps are useful for accessing specific file systems, such as
home directories. The automounts configured in an indirect map are mounted under the same
local parent directory.
Figure 3-4 shows the difference between direct mounts and indirect mounts on an NFS client.
Figure 3-4 Difference Between Direct Mounts and Indirect Mounts
Mounts in a Direct Map
/
Mounts in an Indirect Map
/
= Automounted Directory
In the Mounts in a Direct Map figure, mounts are configured in various places in the local
filesystem and not located under the same parent directory. In the Mounts in an Indirect Map
figure, all the mounts are configured under the same parent directory.
CAUTION: You must maintain filesystems managed by AutoFS, by using the automountd
and automount utilities. Manually mounting and unmounting file systems managed by AutoFS
can cause disruptive or unpredictable results, including but not limited to commands hanging
or not returning expected results. Applications can also fail because of their dependencies on
these mounted filesystems.
Automounting a Remote Directory Using a Direct Map
This section describes how to automount a remote directory using a direct map.
To mount a remote directory using a direct map, follow these steps:
66 Configuring and Administering AutoFS