NFS Services Administrator's Guide

Troubleshooting NFS Services
Performance Tuning
Chapter 8330
To Diagnose NFS Performance Problems
1. Issue the following command on several of your NFS clients:
nfsstat -rc
2. If the timeout and retrans values displayed by nfsstat -rc are
high, but the badxid value is close to zero, packets are being dropped
before they get to the NFS server.
Try decreasing the values of the wsize and rsize mount options to
4096 or 2048 on the NFS clients. See “To Change the Default Mount
Options” on page 46.
See Installing and Administering LAN/9000 Software for
information on troubleshooting LAN problems.
3. If the timeout and badxid values displayed by nfsstat -rc are of
the same magnitude, your server is probably slow. Client RPC
requests are timing out and being retransmitted before the NFS
server has a chance to respond to them.
See “To Improve NFS Server Performance” on page 332.
Try doubling the value of the timeo mount option on the NFS clients.
See “To Change the Default Mount Options” on page 46.
4. If the null value displayed by nfsstat -rc is greater than 1%, the
automounter is trying too frequently to mount a directory from
multiple servers. It sends out null procedure calls to all the
configured servers and mounts the directory from the server that
answers first.
Increase the time between mount attempts by adding the -tm 60
option to the AUTO_OPTIONS variable in
/etc/rc.config.d/nfsconf, as follows:
AUTO_OPTIONS=”-f $AUTO_MASTER -tm 60”
Then, restart the automounter. See “To Restart the Automounter” on
page 92.
Continue to increase the value of the -tm parameter until the null
value displayed by nfsstat is less than 1%.
5. Issue the following command on any machine on the network:
netstat -i