From owner-freebsd-stable  Mon May  1 16:47:32 2000
Delivered-To: freebsd-stable@freebsd.org
Received: from implode.root.com (root.com [209.102.106.178])
	by hub.freebsd.org (Postfix) with ESMTP
	id 1639137B8E8; Mon,  1 May 2000 16:47:28 -0700 (PDT)
	(envelope-from dg@implode.root.com)
Received: from implode.root.com (localhost [127.0.0.1])
	by implode.root.com (8.8.8/8.8.5) with ESMTP id QAA28681;
	Mon, 1 May 2000 16:43:10 -0700 (PDT)
Message-Id: <200005012343.QAA28681@implode.root.com>
To: chad@DCFinc.com
Cc: blk@skynet.be (Brad Knowles), parag@cgt.com, msmith@FreeBSD.ORG,
	freebsd-stable@FreeBSD.ORG
Subject: Re: How good is AMI MegaRAID support? 
In-reply-to: Your message of "Mon, 01 May 2000 16:00:59 PDT."
             <200005012300.QAA18195@freeway.dcfinc.com> 
From: David Greenman <dg@root.com>
Reply-To: dg@root.com
Date: Mon, 01 May 2000 16:43:10 -0700
Sender: owner-freebsd-stable@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

>> 	How fast is fast enough?  Do you need a disk subsystem that can 
>> handle bursts of ~2500 USENET news history database lookups per 
>> second?  What would it take to get to that level?  Do you need to see 
>> rawio read performance (average tranfer size of one sector w/ 64 
>> simultaneous processes) of around 5,000 read operations per second? 
>
>We're running quite a bit more than 5,000 iops/sec on the EMC Symmetrix 
>box that's replacing the A-3500s.
>
>Just depends on what it is you need done.

   TeraSolutions' RAID systems (TSR-2200) as used on ftp.freesoftware.com are
capable of >9,000 IOPS.
   There are other issues to consider when thinking about software RAID-5. The
most important of these is the (lack of) non-volatile write-back cache.

-DG

David Greenman
Co-founder/Principal Architect, The FreeBSD Project - http://www.freebsd.org
Creator of high-performance Internet servers - http://www.terasolutions.com
Pave the road of life with opportunities.


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message