From owner-freebsd-stable Tue Jan 2 6: 6:32 2001 From owner-freebsd-stable@FreeBSD.ORG Tue Jan 2 06:06:29 2001 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from tao.org.uk (genesis.tao.org.uk [194.242.131.94]) by hub.freebsd.org (Postfix) with ESMTP id AC22337B400 for ; Tue, 2 Jan 2001 06:06:28 -0800 (PST) Received: by tao.org.uk (Postfix, from userid 100) id AF5CA3229; Tue, 2 Jan 2001 14:06:16 +0000 (GMT) Date: Tue, 2 Jan 2001 14:06:16 +0000 From: Josef Karthauser To: Matraquilla@cs.com Cc: Roman Shterenzon , Greg Lehey , freebsd-stable@FreeBSD.ORG Subject: Re: vinum malfunction! Message-ID: <20010102140616.B1391@tao.org.uk> Mail-Followup-To: Josef Karthauser , Matraquilla@cs.com, Roman Shterenzon , Greg Lehey , freebsd-stable@FreeBSD.ORG References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from Matraquilla@cs.com on Tue, Jan 02, 2001 at 08:33:58AM -0500 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, Jan 02, 2001 at 08:33:58AM -0500, Matraquilla@cs.com wrote: [cut] > > As to your Vinum sacred cow, when are you going to accept that Vinum shall > (and could) never be more than an experimental beta that should never be > relied upon fully in a production environment. If you want RAID, you get a > RAID controller. If you like to play with explosives and are trying to get > away with cheap or free, by all means play with Vinum or its other software > siblings. > I'm going to jump in here and defend Greg for a moment. There is nothing wrong with doing RAID5 in software. It allows a quick fix without requiring the purchase of hardware for the cases where the machine in question has plenty of spare CPU available (which is most of them by todays standards). It's cool. On the other hand if it doesn't work then it's a nightmare! (Like having bad ram on your raid controller card :). The problem with vinum RAID5 in -stable is that in my experience there are some nasty bugs in it, and I don't believe that Greg has managed to reproduce these himself and so is a bit confused as to what is causing the trouble. I'm worried that he may be inclined to believe that it is only a small minority of people who are having problems with this. I would challange this view because I don't know _anyone_ who is successfully using RAID5 under vinum. They've all migrated away to using dedicated hardware and thus solved their vinum problems that way. I don't know what it's going to take for Greg to get enough information to fix the problem. I spent a week trying to extract a set of debug information for him that was useful enough that he could work from it, but it seems that my week was just wasted because it looks like I didn't capture the bug that he was expecting :(. I have tried to trust my home directory to vinum raid5 but failed. :( To summarise. The idea of software raid 5 is great, but it's got to work otherwise it is dangerous. I note that the BUGS section of the manual page doesn't exist. There should be a warning to potential users that there are known problems that can cause the data to become corrupted in some configurations. Joe To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message