Weird NFS problems
jd at ugcs.caltech.edu
Tue May 31 11:56:13 PDT 2005
Yes, but surely you weren't bridging gigabit and 100Mbit before?
Did you try my suggestion about binding the IP address of the NFS server
to the 100Mbit side?
On Tue, 31 May 2005, Skylar Thompson wrote:
> Jon Dama wrote:
> >Try switching to TCP NFS.
> >a 100MBit interface cannot keep up with a 1GBit interface in a bridge
> >configuration. Therefore, in the long run, at full-bore you'd expect to
> >drop 9 out of every 10 ethernet frames.
> >MTU is 1500 therefore 1K works (it fits in one frame), 2K doesn't (your
> >NFS transactions are split across frames, one of which will almost
> >certainly be dropped, it's UDP so the loss of one frame invalidates the
> >whole transaction).
> >This is the same reason you can't use UDP with a block size greater than
> >MTU to use NFS over your DSL or some such arrangement.
> >Incidentially, this has nothing to do with FreeBSD. So if using TCP
> >mounts solves your problem, don't expect Solaris NFS to magically make the
> >UDP case work...
> The thing is that UDP NFS has been working for us for years. A big part
> of our work is performance analysis, so to change our network
> architecture will invalidate a large part of our data.
> -- Skylar Thompson (skylar at cs.earlham.edu)
> -- http://www.cs.earlham.edu/~skylar/
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