Poor PE4600 NFS performance
aly.dharshi at uleth.ca
Mon Aug 5 19:17:01 CDT 2002
Rick Gaudette wrote:
> It is the onboard broadcom chip.
I am going to venture a personal opinion, I think that Broadcom cards aren't the
best, Intel is better in performance, I wonder if that has anything to do with
it. I guess its worth an expensive experiment to try another card maybe a Intel
or 3Com gig card ??? :) :) :)
> Would this still apply if there are typically only one or two users
> reading at any given time? Our typical use model is that one or two
> users might be trying to read a 1-2 GB data file at any given time.
> That is the type of use model we wish to get the best performance for.
I don't think this would do much in terms of 1-2 users at a go, unless you are
planning on servicing a Computer Science network with 120 Unix workstations and
whole bunch of students. I would consider maybe putting in another gig nic if
you are reading this amount at a go. Later maybe ??
> Anyone have any recommendations here? We have tried a bunch but the
> default seems to work best. The man pages say the default is 8K but
> when we specify 8K we get degraded performance. The defaults seem to
> perform the same as 32K.
I seem to stick to nfs settings in the man pages, the default is 1024bytes. They
seem to claim that thru' put is greatly improved with rsize=wsize=8192bytes. So
I am surprised that you are having a bad performance.
> UDP. I would like to try to use TCP but as far as I can tell the RH
> kernels don't support it. Anyone know how to enable TCP based NFS on RH
Man nfs says that if you add tcp to the end of the options then it will start up
as a tcp nfs system as opposed to udp, RH ???. Again subject to experimenting
adding that at the end of the /etc/fstab line that I provided maybe adding tcp
may do the trick. Most of the Linux NFS is v2 maybe toggling it to version 3 may
provide more improvement ??? (Pure experimentation !)
> A bit more info that I have noticed. nfsstat reports that the number of
> retries is pretty significant compared the number of calls. The clients
> all say that there is 1 retrans for every 3 calls to the PE 4600. This
> doesn't sound good to me but I am not sure how to fix it.
My system seems to provide more information for V3 NFS as opposed to that of V2.
I guess V3 maybe the defaults ?
aly.dharshi at uleth.ca
System Administrator ORS Servers
University of Lethbridge
"A good speech is like a good dress
that's short enough to be interesting
and long enough to cover the subject"
More information about the Linux-PowerEdge