Hi,
Here's the crux of my original posting:
================
We have several systems running OSF1/DUX/Tru64 4.0D up to 5.1A.
Filesystems among these systems are heavily cross-mounted via NFS. Until
now, I have never paid attention to what version of NFS is being served.
As I understand it, nfsd negotiates version between server and client. To
my surprise, some of the machines appear to be serving either NFS2 or NFS3
depending on who is doing the reporting. This was observed by examining
entries in /var/adm/messages for the various machines. (I assume that if
an entry in messages contains the phrase "...NFS2 server rocky...", this
means that rocky was serving via NFS2 -- at least at that particular
moment.)
================
The replies are appreciated and were -- as always -- educational (and I
apologize for not reading some of the man pages a bit closer which would
have answered some of my questions!) Anyway...
My thanks go to:
Robert Fridman fridman_at_ucalgary.ca
system administration account <sysadmin_at_astro.su.se>
"Michael A. Crowley" <mcrowley_at_mtholyoke.edu>
Here are (quoted) excerpts from their replies and other notes that I added...
"NFS mounting up to 4.0G has a bug where under some circumstances, the
nfs mount reverts to V2. This is fixed in 4.0G and above."
To see the versions of NFS that are being used, run "mount -avf" on the
client.
To determine reliably what NFS version is being served by nfsd...
"Sniff the network traffic with tcpdump. It will be obvious what RPC calls
are actually being made. I've just looked at some of my own NFS traffic
(strictly v3) using
pfconfig +c tu0
tcpdump -s 1500 -evv port 2049
"
If using the automounter, "each unmount / mount sequence may cause
a change in which NFS version is being used."
To control what version nfsd uses...
"Client-side, you can specify vers=2 or vers=3 as a mount option.
Server-side, I see no documented option to disable either version;
of course you could roll your own nfsd (difficult) and/or your own
portmap to avoid advertising mountd v1 and NFS v2 services (much
easier, but probably not foolproof)."
What are the performance hits that we would take if we are not always
operating at NFS3 or if for some reason some machines are switching back
and forth?
"My main concern would be features like large file support, not performance."
Thanks,
Peyton Bland
University of Michigan
Department of Radiology
Received on Fri Mar 01 2002 - 19:06:47 NZDT