NFS Services Administrator's Guide (B1031-90072, March 2011)

request to complete before issuing another request. This can be performed only for NFSv2.
The default option for NFSv3 is async.
Improving NFS Client Performance
□ For files and directories that are mounted read-only and never change, set the actimeo mount
option to 120 or greater in the /etc/fstab file on your NFS clients.
□ If you see several “server not responding” messages within a few minutes, try doubling
the value of the timeo mount option in the /etc/fstab file on your NFS clients.
□ If you frequently see the following message when attempting access to a soft-mounted directory,
NFS operation failed for server servername: Timed out
try increasing the value of the retrans mount option in the /etc/fstab file on the NFS
clients. Or, change the soft mount to an interruptible hard mount, by specifying the hard and
intr options (the defaults).
□ Enter the following command on the NFS server, to find out the block size of the server’s
filesystem:
/usr/sbin/tunefs -v devicefilename
On the NFS clients, set the wsize and rsize mount options to the bsize value displayed
by tunefs.
□ On the NFS clients, look in the /etc/fstab file for “stepping-stone” mounts (hierarchical
mounts), as in the following example:
thyme:/usr /usr nfs defaults 0 0
basil:/usr/share /usr/share nfs defaults 0 0
sage:/usr/share/lib /usr/share/lib nfs defaults 0 0
Wherever possible, change these “stepping-stone” mounts so that whole directories are
mounted from a single NFS server.
Stepping-stone (hierarchical) mounts, like the one in the example above, cause more NFS
requests than mounts from a single server. In the example, if a client wants access to something
in /usr/share/lib, a request must be sent to server thyme, then to server basil, and
finally to server sage.
For more information on the stepping-stone mounts, see “Changing the Default Mount Options”
(page 38).
Logging and Tracing of NFS Services
This section tells you how to start the following tools:
• “AutoFS Logging” (page 75)
• “AutoFS Tracing” (page 76)
• “Logging for the Other NFS Services” (page 101)
• “Logging With nettl and netfmt” (page 102)
• “Tracing With nettl and netfmt” (page 103)
Logging for the Other NFS Services
You can configure logging for the following NFS services:
• rpc.rexd
• rpc.rstatd
• rpc.rusersd
Logging and Tracing of NFS Services 101