From owner-freebsd-hackers  Sat Jun 21 17:07:36 1997
Return-Path: <owner-hackers>
Received: (from root@localhost)
          by hub.freebsd.org (8.8.5/8.8.5) id RAA27296
          for hackers-outgoing; Sat, 21 Jun 1997 17:07:36 -0700 (PDT)
Received: from sendero-ppp.i-connect.net (sendero-ppp.i-Connect.Net [206.190.143.100])
          by hub.freebsd.org (8.8.5/8.8.5) with SMTP id RAA27288
          for <hackers@FreeBSD.ORG>; Sat, 21 Jun 1997 17:07:28 -0700 (PDT)
Received: (qmail 2235 invoked by uid 1000); 22 Jun 1997 00:07:34 -0000
Message-ID: <XFMail.970621170734.Shimon@i-Connect.Net>
X-Mailer: XFMail 1.2-alpha [p0] on FreeBSD
Content-Type: text/plain; charset=iso-8859-8
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
In-Reply-To: <199706211729.TAA02164@yedi.iaf.nl>
Date: Sat, 21 Jun 1997 17:07:34 -0700 (PDT)
Organization: Atlas Telecom
From: Simon Shapiro <Shimon@i-Connect.Net>
To: Wilko Bulte <wilko@yedi.iaf.nl>
Subject: Re: Announcement: New DPT RAID Controller Driver Available
Cc: hackers@FreeBSD.ORG, gjennejohn@frt.dec.com,
        (Nadav Eiron) <nadav@cs.technion.ac.il>
Sender: owner-hackers@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk


Hi Wilko Bulte;  On 21-Jun-97 you wrote: 
> As Nadav Eiron wrote...
> > On Fri, 20 Jun 1997 garyj@frt.dec.com wrote:
> 
> > > jkh@time.cdrom.com writes:
> > > > providing forced airflow past the drives, then I suppose the
> plastic
> > > > sled construction wouldn't really matter much, would it? :-)
> 
> > My previous employer had a pretty big OpenVMS cluster with giant SW800
> > racks (rough estimate - about 500 drives, total most 7200rpm). When
> > filling up one of these racks, DEC recommends that you add a shelf of
> fans
> 
> Right, the 'fan tray' as it is called.
> 
> > at the bottom to force some more air into it, but other than that, heat
> > doesn't seem to be a problem. These plastic canisters seem to have
> great
> > air flow. Just place your hand over the warm air outlet of one of these
> > SW800s and feel how much heat it evacuates from the drives.
> 
> It's interesting to note that when the 7200 rpm drives were introduced
> also new fan models were introduced to be put on the back of the storage
> shelves. The idea is that one fan is allowed to fail without causing a
> disk meltdown. The older fans could not keep up in such a case
> so the newer dual speed fans are needed. In case a fan fails, the 
> remaining fan switches to double speed.

Like I said, these hobyists at DEC really do not know the first thing about
disk subsystems.  Give me a good PC.  Grrrrr...  :-)

Any idea about my network-scsi interaction?

Simon