Red Hat Summit Red Hat SummitSupportConsoleDevelopersStart a trialContact

9.4.3. 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:
    Copy to Clipboard Toggle word wrap 
    automount:    files nis
  • The auto.master file contains the following
    Copy to Clipboard Toggle word wrap 
    +auto.master
  • The NIS auto.master map file contains the following:
    Copy to Clipboard Toggle word wrap 
    /home auto.home
  • The NIS auto.home map contains the following:
    Copy to Clipboard Toggle word wrap 
    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:
Copy to Clipboard Toggle word wrap 
/home ­/etc/auto.home
+auto.master
The /etc/auto.home map contains the entry:
Copy to Clipboard Toggle word wrap 
*    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, to augment the site-wide auto.home map with just a few entries, create an /etc/auto.home file map, and in it put the new entries. At the end, include the NIS auto.home map. Then the /etc/auto.home file map will look similar to:
Copy to Clipboard Toggle word wrap 
mydir someserver:/export/mydir
+auto.home
Given the NIS auto.home map listed above, ls /home would now output:
Copy to Clipboard Toggle word wrap 
beth joe mydir
This last example works as expected because autofs does not 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.
Back to top
Red Hat logoGithubredditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust. Explore our recent updates.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

Theme

© 2025 Red Hat, Inc.