Tue Nov 9 01:00:01 PST 2010
"The experimental kernel from VA Linux, kernel 2.2.16-8.ext3.3, are at:
It is based on 2.2.16-8 from RedHat rawhide with NFS V3, ext3 0.0.2f,
new pcmcia-cs, ....., many other changes. There is no support
whatsoever. If you have problems, which cannot be reproduced under
stock 2.2.16 nor 2.2.16-8 from RedHat, post them to the NFS mailing"
jdavis at hess.com
If you pick up a starving dog and make him prosperous,
he will not bite you. This is the principal difference between
a dog and a man.
-- Mark Twain
----- Original Message -----
From: "Jakob Østergaard" <jakob at ostenfeld.dtu.dk>
To: "Josip Loncaric" <josip at icase.edu>
Cc: "Beowulf mailing list" <beowulf at beowulf.org>
Sent: Friday, August 18, 2000 3:32 PM
Subject: Re: NFS 100:1 performance loss
On Fri, 18 Aug 2000, Josip Loncaric wrote:
> Has anyone seen this NFS performance problem?
> Our Beowulf has two servers w/RAID-0 arrays which deliver 45MB/s,
> connected via Gigabit Ethernet. The machines are dual PIII/500 systems
> with 512MB of RAM each. We are running Red Hat 6.2 updated to kernel
> 2.2.16-3 and recently we updated to nfs-utils-0.1.9.1-1. We are running
> 16 kernel nfsd threads on each machine. Here is how long it takes to
> copy a 28,955,860 byte file from machine 1 to machine 2:
> rcp: 1.04 seconds (27.8 MB/s, where 1MB=10^6B)
> ftp: 1.12 seconds (25.8 MB/s)
> NFS 1KB: 12.35 seconds ( 2.3 MB/s, using rsize=wsize=1024)
> NFS 8KB: 129.42 seconds ( 0.2 MB/s, using rsize=wsize=8192)
> Clearly, there is something very wrong with NFS, particularly with 8KB
> rsize/wsize (which should have improved performance!). Our system
> manager tells me that reduced Linux NFS performance with 8KB rsize/wsize
> is a known problem, but even at 1KB our NFS is getting less than 10% of
> the rcp or ftp performance.
> Any ideas?
You do use the kernel nfs server right ? knfsd, not the old
userspace nfs daemon...
Our NFS server gets us some 5 MB/s over 100MBit, which is
pretty good I think. Linux NFS is not ``excellent'' yet, but
with the kernel NFS server it should be better than ``horrible''
at least :)
Eventually, you could try the NFS patches (for both client and
server) available somewhere at sourceforge (don't have the URL,
but a quick search should get you there). They should resolve
most of the annying errors you see with Linux NFS, and they should
improve performance too I think. We don't use them yet however,
so I don't have any experience to go with that one.
: jakob at ostenfeld.dtu.dk : And I see the elder races, :
:.........................: putrid forms of man :
: Jakob Østergaard : See him rise and claim the earth, :
: OZ9ABN : his downfall is at hand. :
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