Subject: Re: multiple processors on NFS servers
To: Michael Richardson <email@example.com>
From: Thor Lancelot Simon <firstname.lastname@example.org>
Date: 04/12/2000 22:43:21
On Wed, Apr 12, 2000 at 08:13:44PM -0400, Michael Richardson wrote:
> Given that CPU speeds have increased an order of magnitude faster than
> disk speeds, is there any advantage to having multiple CPUs on NFS servers?
> It used to be that NFS servers were always CPU bound, but that was in the
> days of 20Mhz '030s and 40Mhz Sparc CPUs. Are there any papers that describe
> what happens now?
Have a look at SPECsfs results. The current leaders have loads-o-disks and
generally have anywhere from two to 12 CPUs.
It is possible to have to do quite a bit of processing to handle a single
RPC operation. Multiple CPUs do seem to help.
Interestingly, using FDDI can even let you beat small-frame GigE in
NFSops/sec because the frame size is four times as large.
Unfortunately, I've had some fairly negative experiences with NetBSD as
a heavily-used NFS server, and significantly worse ones with FreeBSD. The
only really good NFS out there that you can run on your fileserver built
from a PCseems to be Sun's. I strongly recommend Solaris 8 (which comes
with a number of features that accellerate NFS) with DiskSuite's metadata
logging as an NFS server.