From owner-freebsd-hackers Sun Jul 19 00:09:26 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id AAA09357 for freebsd-hackers-outgoing; Sun, 19 Jul 1998 00:09:26 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from freebie.lemis.com (freebie.lemis.com [139.130.136.133]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id AAA09352 for ; Sun, 19 Jul 1998 00:09:22 -0700 (PDT) (envelope-from grog@freebie.lemis.com) Received: (from grog@localhost) by freebie.lemis.com (8.9.1/8.9.0) id QAA00814; Sun, 19 Jul 1998 16:39:00 +0930 (CST) Message-ID: <19980719163859.H435@freebie.lemis.com> Date: Sun, 19 Jul 1998 16:38:59 +0930 From: Greg Lehey To: Wilko Bulte Cc: tlambert@primenet.com, gibbs@plutotech.com, andre@pipeline.ch, Matthew.Alton@anheuser-busch.com, Hackers@FreeBSD.ORG Subject: Re: Software RAID-5 performance References: <19980715094757.P15083@freebie.lemis.com> <199807152003.WAA03283@yedi.iaf.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.91.1i In-Reply-To: <199807152003.WAA03283@yedi.iaf.nl>; from Wilko Bulte on Wed, Jul 15, 1998 at 10:03:32PM +0200 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wednesday, 15 July 1998 at 22:03:32 +0200, Wilko Bulte wrote: > As Greg Lehey wrote... >> On Tuesday, 14 July 1998 at 20:05:16 +0200, Wilko Bulte wrote: >> 3. As long as the disks didn't physically fail, rebuild the RAID-5 >> set after rebooting. > > I don't think this solves it, as you don't know which block is up to date > and which block is not. Or do I miss your point? Well, you'd have to have some convention like writing the data block before the parity block. Then you could assume that if you found a parity error, the parity block would be wrong, so you could fix it. Of course, any other consistent assumption would work as well, but having the parity block written last would mean you could bring up the array read-only while you were rebuilding it. Greg -- See complete headers for address and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message