From owner-freebsd-stable Mon May 1 15:28:36 2000 Delivered-To: freebsd-stable@freebsd.org Received: from trinity.skynet.be (trinity.skynet.be [195.238.2.38]) by hub.freebsd.org (Postfix) with ESMTP id CC6E037B782; Mon, 1 May 2000 15:28:33 -0700 (PDT) (envelope-from blk@skynet.be) Received: from [195.238.24.94] (dialup684.brussels2.skynet.be [195.238.25.172]) by trinity.skynet.be (Postfix) with ESMTP id D839118144; Tue, 2 May 2000 00:28:08 +0200 (MET DST) Mime-Version: 1.0 X-Sender: blk@pop.skynet.be Message-Id: In-Reply-To: <93707.957044958@pinhead.parag.codegen.com> References: <93707.957044958@pinhead.parag.codegen.com> Date: Tue, 2 May 2000 00:12:15 +0200 To: Parag Patel , Mike Smith From: Brad Knowles Subject: Re: How good is AMI MegaRAID support? Cc: freebsd-stable@FreeBSD.ORG Content-Type: text/plain; charset="us-ascii" ; format="flowed" Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG At 2:49 PM -0700 2000/4/29, Parag Patel wrote: > Out of curiosity, how would a PCI-RAID (SCSI) adapter compare with > vanilla PCI-SCSI cards and vinum? It seems to me that the host CPU(s) > are much faster than the processors on the PCI-SCSI adapters. In fact, this is precisely what Greg Lehey and some others have told me, and my own experience has confirmed this. > Or are > both of these "fast-enough" and thus performance differences are largely > an irrelevent consideration? (They both have similar software issues > but I suspect vinum is easier to debug. :) 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? If so, then I've only barely managed to get there. Sure, vinum will be easier to debug. The only issue is how much debugging do you believe that the hardware RAID vendors have done before they ship their product, versus how much debugging do you think vinum gets? Myself, I'm learning to put a lot more trust in Greg.... -- These are my opinions -- not to be taken as official Skynet policy ====================================================================== Brad Knowles, || Belgacom Skynet SA/NV Systems Architect, Mail/News/FTP/Proxy Admin || Rue Colonel Bourg, 124 Phone/Fax: +32-2-706.13.11/12.49 || B-1140 Brussels http://www.skynet.be || Belgium To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message