NFS Services Administrator's Guide (B.11.31.02) January 2008

Configuring Replicated Servers for an AutoFS Directory
This section describes how to configure multiple replicated servers for an AutoFS directory.
Modify the entry that mounts the remote directory to list multiple servers in the appropriate
map, as follows:
• If the remote directories have the same name on every server, use a syntax such as the
following from an indirect map:
man -ro broccoli,cabbage,cauliflower:/usr/share/man
• You can assign a weighting factor to the servers by specifying a number in parentheses after
each server name. If the server has a lower weighting number specified, it is likely to be
selected. Servers that have no weight factor specified have a default weight of zero and are
most likely to be selected.
man -ro broccoli(1),cabbage(2),cauliflower(3):/usr/share/man
However, server proximity is more important than the weighting factor you assign. A server
on the same network segment as the client is more likely to be selected, than a server on
another network segment, regardless of the weight you assign. The weighting factor is taken
into account only when deciding between servers with the same network proximity.
• If the remote directory has a different name on different servers, use a syntax such as the
following from a direct map:
/nfs/proj2/schedule -ro \
broccoli:/export/proj2/schedule, \
cauliflower:/proj2/FY07/schedule
To configure multiple replicated servers for a directory, follow these steps:
1. Create and configure the /etc/netmasks file. AutoFS requires the /etc/netmasks file
to determine the subnets of local clients in a replicated multiple server environment.
The /etc/netmasks file contains IP address masks with IP network numbers. It supports
both standard subnetting as specified in RFC-950, and variable-length subnetting as specified
in RFC-1519. For standard subnetting, the file must contain a single line for each network.
This provides the network number and the network mask to be used on that network. Specify
the network number and the mask using the conventional IP dot (.) notation. The network
number must be either a class A, B, or C network number. For example:
network number netmask
128.32.0.0 255.255.255.0
For variable length subnetting, the /etc/netmasks file must contain a line for each subnet,
where the first field refers to the subnet and the second field refers to the netmask. The
format for specifying these fields is the same as that of standard subnetting.
Example of using the /etc/netmasks File
The following example shows how AutoFS uses the /etc/netmasks file to determine the local
client subnets in a multiple-server environment. In this example, servers basil and thyme
export/nfs/mount. The IP address for server basil is 15.43.232.30, and the IP address for the
server, thyme is 15.244.10.20:
# /etc/auto_direct file
/nfs_mount basil,thyme:/nfs/mount
#/etc/netmasks file on the client sage:
#network number netmask
15.43.234.210 255.255.248.0
AutoFS uses the /etc/netmasks file to determine that the masked value for the subnet of
basil and the network number is the same (15. 42. 232. 0). This shows that the client is on the
same network as basil. AutoFS then mounts /nfs/mount from basil on the local subnet.
Advanced AutoFS Administration 77