HP-UX System Administrator's Guide: Routine Management Tasks

2. Select Tools → Network Services Configuration → Networked File Systems
→ Share/Unshare File Systems (Export FS). The Share page will be displayed.
3. Select the desired file system and a table of shared file properties will be displayed.
Check to see that Asynchornous Writes are allowed.
If needed you can change the setting of the Asynchronous Writes flag, while the
file system is still mounted and shared.
• Select View/Modify Shared (exported) File System... to display the setting for
the selected file system. Check the Allow Asynchronous Writes box and click on
OK.
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” (page 192) 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 more readable
on an 80-column display.
The column to watch most closely is po. If it is not zero, the system is paging. If the
system is paging consistently, you probably need more RAM.
Checking for Socket Overflows with netstat -s
Although many different processes use sockets, and can contribute to socket overflows,
regular socket overflows on an NFS server may indicate that you need to run more
nfsd processes. The command,
netstat -s | grep overflow
will show you a cumulative number for socket overflows (since the last boot). If you
see this number rising significantly, and NFS clients are seeing poor response from this
196 Managing System Performance