Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Administering a System: Managing Printers, Software, and Performance

Managing System Performance

Chapter 7732

Run SAM on the NFS server, go to Networking and

Communications/Networked File Systems/Exported Local File

Systems, select each exported ﬁle system in turn, pull down the Actions

menu and select View More Information. This screen shows

Asynchronous Writes as either Allowed or Not Allowed.

You can change the setting of the Asynchronous Writes ﬂag in SAM,

while the ﬁle system is still mounted and exported.

Go to Exported Local File Systems, select the exported ﬁle system for

which you want to allow (or prevent) asynchronous writes, pull down the

Actions menu and select Modify. Then select Yes or No under

Asynchronous Writes.

Checking for Server Overload with nfsstat -rc

Run nfsstat -rc on an NFS client to get an idea of how the server is

performing.

You’ll get a report that looks like this:

Client rpc:

calls badcalls retrans badxid timeout wait newcred

43467543 848 6 3868 27942 0 0

badxid should be small in relation to timeout. If these numbers are

nearly the same, it may mean the server is overloaded and generating

duplicate replies to RPC requests that have timed out and been

retransmitted. Check the server’s memory, disk and NFS conﬁguration;

see the “Guidelines” on page 727 in the previous section.

NOTE A badxid that is close to zero and a large number for timeout may

indicate packets are being dropped; that is, the client’s requests are

timing out because they never reach the server. In this case the problem

is likely to be a network card on the server or client, or the network

hardware.

Measuring Memory Usage with vmstat

vmstat displays a wealth of information; use the -n option to make it