Before you automount a remote directory, decide whether you
want to use a direct or indirect AutoFS map.
If your automounted directory must share the same parent directory with
local or standard-mounted directories, you can choose a direct map.
Table 3-1 “Direct Versus Indirect AutoFS Map Types” lists the advantages
and disadvantages of direct and indirect AutoFS maps.
Table 3-1 Direct Versus Indirect AutoFS Map Types
Direct
Map | Indirect
Map |
|---|
Advantage: A
user can view the contents of a direct-mounted directory, using
the ls command. If the contents are not currently mounted, ls mounts them. | Advantage: AutoFS
allows a user to view the available mount points for indirect maps
without actually mounting each filesystem when browsability is enabled
by default. |
Advantage: Direct-mounted automounted
directories can share the same parent directory with local, or standard-mounted files
and directories. | Disadvantage: An
indirect map hides any local, standard-mounted, or direct-mounted
files or directories under the mount point for the map. |
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: If
you modify an indirect map, AutoFS will see the changes the next
time it mounts the directory. You need not force AutoFS to reread
its maps. |
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. | 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. |
How AutoFS
Sets Up Direct and Indirect Mounts |
 |
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.
The automounts configured in an indirect map are mounted under
the same local parent directory.
Figure 3-2 “Difference Between Direct Mounts and Indirect
Mounts” shows the difference
between direct mounts and indirect mounts on an NFS client.
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