10.3.3. Overriding or Augmenting Site Configuration Files
It can be useful to override site defaults for a specific mount point on a client system. For example, consider the following conditions:
Automounter maps are stored in NIS and the /etc/nsswitch.conf
file has the following directive:
automount: files nis
The auto.master
file contains the following
+auto.master
The NIS auto.master
map file contains the following:
/home auto.home
The NIS auto.home
map contains the following:
beth fileserver.example.com:/export/home/beth
joe fileserver.example.com:/export/home/joe
* fileserver.example.com:/export/home/&
The file map /etc/auto.home
does not exist.
Given these conditions, let's assume that the client system needs to override the NIS map auto.home
and mount home directories from a different server. In this case, the client will need to use the following /etc/auto.master
map:
/home /etc/auto.home
+auto.master
And the /etc/auto.home
map contains the entry:
* labserver.example.com:/export/home/&
Because the automounter only processes the first occurrence of a mount point, /home
will contain the contents of /etc/auto.home
instead of the NIS auto.home
map.
Alternatively, if you just want to augment the site-wide auto.home
map with a few entries, create a /etc/auto.home
file map, and in it put your new entries and at the end, include the NIS auto.home
map. Then the /etc/auto.home
file map might look similar to:
mydir someserver:/export/mydir
+auto.home
Given the NIS auto.home
map listed above, ls /home
would now output:
beth joe mydir
This last example works as expected because autofs
knows not to include the contents of a file map of the same name as the one it is reading. As such, autofs
moves on to the next map source in the nsswitch
configuration.