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Message-ID: <19981216134847.A12105@marvin.ece.utexas.edu>
Date: Wed, 16 Dec 1998 13:48:47 -0600
From: "Brian C. Grayson" <bgrayson@marvin.ece.utexas.edu>
To: Mason Loring Bliss <mason@acheron.middleboro.ma.us>
Cc: netbsd-advocacy@NetBSD.ORG
Subject: Re: Sun jumping on Linux bandwagon
References: <199812121158.DAA11187@cue.bc.ca> <m3lnk9p6fg.fsf@trantor.cosmic.com> <19981216084649.H10788@acheron.middleboro.ma.us>
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In-Reply-To: <19981216084649.H10788@acheron.middleboro.ma.us>; from Mason Loring Bliss on Wed, Dec 16, 1998 at 08:46:49AM -0500

On Wed, Dec 16, 1998 at 08:46:49AM -0500, Mason Loring Bliss wrote:
> 
> Hm... Last I checked, -current's NFS implementation had some bugginess.
> I assume nothing has changed, although I haven't tried it in a while. My
> last results were that without throttling my NFS transfers, a process
> writing anything significant to a remote disk would hang such that only
> rebooting the system would kill it.
> 
> When last I played with NFS on a GNU/Linux box, NFS worked like a charm.
> At the least, I didn't have to kill my NFS performance to keep things from
> locking up.

  Are you running on 100Mb Ethernet, by any chance?  And do
your server Ethernet cards not support DMA?  If so --- I've had
problems with NFS on *BSD machines with that, and so have
others.  The quickie solution is, restrict your wsize to be
smaller than an Ethernet packet, i.e., use 1024 bytes.  I can
give more details in private if desired.  The symptom without the
fix is that any process trying to write more than a 1Kbyte chunk
of data at once will hang in the D state, and pretty soon all
of NFS is hung.

  My experience has been completely the opposite from yours for
10Mb Ethernet, although I'm running -current from a few months ago. 
Linux NFS problems:  dropped characters (caused corruption of
72 CPU-days of simulations), easily-hung servers when linking,
not great performance, no true NFSv3 support (thus, no client-side
write caching).  NetBSD NFS has been wonderful in comparison, in
our experience.

  Brian
-- 
"Time for a reality check!"  - Dr. Andy Boyd, STAT 381/ELEC 331/MASC 381