Managing NFS

[John Jimenez]

Lately my disks have been getting hammered. Top shows no processes going on, but Glance shows the disks being hammered off and on throughout the day. We have exported local files via NFS, and I suspect that it is some SQL servers on Microsoft 2000 Servers that are hammering my production system on the HP. On the HP 11i is there a way I can monitor what is happening via NFS.

[G. Vrijhoeven · Accepted solution]

Hi,

Yes there is.
nsfstat :
http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B9106-90008/B9106-90008_top.html&con=/hpux/onlinedocs/B9106-90008/00/02/265-con.html&toc=/hpux/onlinedocs/B9106-90008/00/02/265-toc.html&searchterms=1M%7cnfsstat&queryid=20040505-124635

glance / perfview can monitor nfs stats.

HTH,

Gideon

[John Jimenez]

Thank you.. I checked out the man pages and to display everything, but reinitialize nothing

nfsstat -cnrs

Is this the way it is normally run?

[G. Vrijhoeven]

Hi again John,

I would go for only the -s (Display server information) -r (Display RPC information)

# nfsstat -sr

I understand you are the server side ( export side not the mount ( client) side.


HTH,

Gideon

[A. Clay Stephenson]

In your case, your are not really interested in client data; all you want is server data so simply nfsstat -ns should be sufficient.

You may want to be logged in as root and first issue an nfsstat -nsz to zero the server statistics. You then can use nfsstat -ns at intervals to see how the various metrics are growing over time.

You don't need to specify /stand/vmunix; that is the default.

By the way, a heavily used NFS Server is an example of a box that can benefit from rather large buffer cache settings and this could have the added benefit of reducing your disk activity.

[John Jimenez]

Thanks for all the help guys. If figures that the disk I/O is now quiet, but next time it happens I will try it

[Brian Hackley]

John,

Use GLANCE to check this. Hit the "n" key
to bring up the NFS statistics. Look on the left Column for Inbound activity. The display is dynamic. This shows you EXACTLY which systems are hammering your NFS server.
It does not show you which filesystem export is involved but check your /etc/exports file vs. your disk display in glance (or sar -d) and that should give you a good idea whats going on.

If this does not get you want you need, you could always hook up a sniffer or use Ethereal on a PC on the network to decode the traffic and then break out the NFS File Handle info using the layout presented in Dave Olker's book "Optimizing NFS Performance"; that will show you the Filesystem and inode # involved in each request.

Regards,
-> Brian Hackley

[Ted Buis]

As previously mentioned Dave Olker's book is very useful for understanding NFS on HP-UX.

[Geoff Wild]

This is a good doc on "performance tuning NFS"

http://h21007.www2.hp.com/dspp/tech/tech_TechDocumentDetailPage_IDX/1,1701,952,00.html

Rgds...Geoff

[John Jimenez]

Thanks you for the suggestions. I will review the URL and that is super that I can see it from Glance too.