NFS Services Administrator's Guide (B.11.31.04) March 2009

the same side of the gateway as the NFS client is always preferred. For multiple servers
outside the local network, and with no weighting factors assigned, the server with the
lowest response time is used for the mount.
Multiple servers provide users with reliable access to a mounted directory. If one server
is down, the directory can be mounted from another. Moreover, multiple servers provide
some load balancing across the network; a server that is not busy responds more quickly
to an AutoFS poll than one that is heavily loaded. The directory is mounted from the
server that is not busy.
If the list of multiple servers contains a combination of servers that includes all versions
of the NFS protocol, then AutoFS selects a subset of servers with the highest NFS
protocol version configured. For example, a list contains a number of servers configured
with the NFSv4 protocol, and a few servers configured with the NFSv2 protocol. AutoFS
will use the subnet of servers configured with the NFSv4 protocol, unless a server
configured with the NFSv2 protocol is closer.
Including a Map in Another Map
If you want your map to refer to an external map, you can do so by including the
external map in your map. The entries in the external map are read as if they are part
of your map.
To include the contents of an AutoFS map in another AutoFS map, add a plus (+) sign
before the map name, as in the following example:
# /etc/auto_home file
# local mount-point mount options remote server:directory
basil -nosuid basil:/export/home/basil
+auto_new
Assume that the /etc/auto_home map is listed in the master map with the following
line:
/home /etc/auto_home
If a user, whose home directory is in /home/basil, logs in, AutoFS mounts the
/export/home/basil directory, from the host, basil.
If a user, whose home directory is in /home/sage, /home/thyme, or any subdirectory
of /home other than basil, logs in, AutoFS consults the auto_home map for
information on mounting the user’s home directory.
The plus (+) sign instructs AutoFS to look up a different map for the information it
needs to mount the directory. If the map name following the plus sign begins with a
slash, AutoFS assumes that it is a local file. If the map name contains no slashes, AutoFS
uses the Name Service Switch to determine whether it is a file, NIS map, or an LDAP
map.
You can include an AutoFS map inside a local file, but not inside an NIS or LDAP map.
For more information on including a map in another map, see automount(1M).
Advanced AutoFS Administration 97