Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!lot!ables
From: ables@lot.ACA.MCC.COM (King Ables)
Newsgroups: comp.sys.sequent
Subject: Re: Problems with NFS (Sequent <-> Sun)
Message-ID: <1214@lot.ACA.MCC.COM>
Date: 28 Sep 90 14:09:53 GMT
References: <1032@dcl-vitus.comp.lancs.ac.uk>
Organization: MCC ACT Program, Austin, TX
Lines: 51

From article <1032@dcl-vitus.comp.lancs.ac.uk>, by se@comp.lancs.ac.uk (Steve Elliott):
> 
> Apparently SparcStations throw out Ethernet packets at such a speed
> that the Sequent can't keep up with it.

If true, this is very interesting.  I saw the same thing happen a few years
ago.

We had a Balance 8000 and a bunch of Sun-2s (I told you it was a few years
ago!) on our net.  The day we got Sun-3s and put them on the net, the
Balance ethernet interface started hanging (this was before the NFS port,
so this was just plain old rlogin/rsh access).  You could reboot and it
would fix it for a while, but soon it would hang again.  Eventually the
SCED board had a new rev. released and all was ok again.  The story then
was the same.  The Sequent hardware just wasn't able to keep up with
the Sun hardware (I think this instance was back-to-back packets which
hadn't been done before).

Let me preface the following criticism with some praise, though.  Sequent
was VERY cooperative and basically busted their butts to solve the problem
for us.  They sent people down a couple of times to look at it (the fact
that a couple of other customers in the area were also having the same problem
probably didn't hurt, though).  And in all the time I ever dealt with them
from a tech. support standpoint, I found them to be far and away better than
any other computer company I've ever dealt with before or since.

The thing that worried me was they obviously weren't designing their interfaces
according to published specs.  They seemed to be looking at what was out there
and designing to coexist with it.  When somebody made a breakthrough of speed
or capacity which was still within the spec., it fouled them up.  This doesn't
seem real bright.  And from this recent problem, it sounds like they still 
may be doing this.  Seems like after being burned once they wouldn't do that
again (fool me once, shame on you, fool me twice, shame on me, that sort of
thing).

Obviously having to SLOW DOWN your Suns is not a good solution.  I expect
Sequent will be working on a solution for you, but if it's BAD (Broken As
Designed) it may not come quickly.

Do other companies have this kind of trouble?  I flashed on the posting since
I've seen it from Sequent before and I've never seen it myself or heard of
it happening to other vendors.

On the other hand, it's the ONLY significant problem I've ever seen out
of Sequent, so from that standpoint it's not so bad.
-----------------------------------------------------------------------------
King Ables                    Micro Electronics and Computer Technology Corp.
ables@mcc.com                 3500 W. Balcones Center Drive
+1 512 338 3749               Austin, TX  78759
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We don't inherit the Earth from our parents, we borrow it from our children.