NFS Services Administrator's Guide (5900-1632, August 2011)

Consider the following scenario where the AutoFS master map, /etc/auto_master, and the
indirect map, /etc/auto_indirect, are on the NFS client, sage. Following are the contents
of the master map, the /etc/auto_master file, which contains a single indirect map entry:
# /etc/auto_master file
# local mount-point map name mount options
/nfs/desktop /etc/auto_indirect
Following are the contents of the indirect map, /etc/auto_indirect, which contains the local
mount-points on the client and the references to the directories on the server:
# /etc/auto_indirect file
# local mount-point mount options remote server:directory
/test -nosuid thyme:/export/project/test
/apps -nosuid basil:/export/apps
Enter the following commands to view the contents of the /nfs/desktop directory:
cd /nfs/desktop
ls
The ls command displays the following:
test apps
The test and apps subdirectories are the potential mount-points. However, they are not currently
mounted. To mount test and apps, enter the following commands:
cd /nfs/desktop/test
cd /nfs/desktop/apps
Concurrent Mount And Unmount
AutoFS performs concurrent mounts and unmounts, using the automountd daemon. For every
mount and unmount request sent to the automountd daemon, a thread is created. This enables
AutoFS to concurrently service multiple mounts and unmounts. This also prevents the service from
hanging if a server is unavailable.
NFS Loopback Mount
By default, AutoFS uses the Loopback Filesystem (LOFS) mount for locally mounted filesystems.
AutoFS provides an option to enable loopback NFS mounts for the local mount. Use the
automountd command with the -L option to enable the loopback NFS mounts for locally mounted
filesystems. This option is useful when AutoFS is running on a node that is part of a High Availability
NFS environment.
Client-side Failover Support
AutoFS enables a mounted NFS read-only filesystem to transparently switch over to an alternate
server if the current server goes down. AutoFS can make use of this feature if the NFS client supports
client-side failover. For more information on client-side failover, see “Enabling Client-Side Failover”
(page 36).
Secure NFS Support
AutoFS supports secure NFS filesystems if the NFS client supports mounting of secure directories.
For more information on Secure NFS, see “Secure Sharing of Directories ” (page 24).
Reliable NFS Ping
In a congested network, the default timeout for an NFS ping may be too short, possibly resulting
in failed mounts. AutoFS supports the -retry= n mount option for an NFS map entry to configure
the ping timeout value. Increasing the value raises the probability for the ping to succeed.
52 Configuring and Administering AutoFS