From owner-freebsd-questions Sun Jan 16 5:55:31 2000 Delivered-To: freebsd-questions@freebsd.org Received: from yana.lemis.com (yana.lemis.com [192.109.197.140]) by hub.freebsd.org (Postfix) with ESMTP id 1DF0E14DBF for ; Sun, 16 Jan 2000 05:55:27 -0800 (PST) (envelope-from grog@mojave.worldwide.lemis.com) Received: from mojave.worldwide.lemis.com (m15.chn.vsnl.net.in [202.54.43.210] (may be forged)) by yana.lemis.com (8.8.8/8.8.8) with ESMTP id AAA00737; Mon, 17 Jan 2000 00:25:11 +1030 (CST) (envelope-from grog@mojave.worldwide.lemis.com) Received: (from grog@localhost) by mojave.worldwide.lemis.com (8.9.3/8.9.3) id TAA04889; Sun, 16 Jan 2000 19:05:20 +0530 (IST) (envelope-from grog) Date: Sun, 16 Jan 2000 19:05:20 +0530 From: Greg Lehey To: Tyler Barnett Cc: freebsd-questions@FreeBSD.ORG Subject: Re: CCD recovery questions Message-ID: <20000116190520.P3413@mojave.worldwide.lemis.com> Reply-To: Greg Lehey References: <200001130307.WAA78568@heathers.stdio.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0i In-Reply-To: <200001130307.WAA78568@heathers.stdio.com>; from tbarnett@stdio.com on Wed, Jan 12, 2000 at 10:07:09PM -0500 WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF 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-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG [Format recovered--see http://www.lemis.com/email/email-format.html] Please limit your messages to < 80 characters per line (unless you're quoting verbatim output). On Wednesday, 12 January 2000 at 22:07:09 -0500, Tyler Barnett wrote: > I'm running 3.3 stable, and created a 12GB CCD mirror from 2 > identical disk drives. > > To test the scenario of one of them failing, I shutdown the system > and unplugged one. During boot the ccd driver refused to config it. > The system dropped into single-user mode for an fsck. Fun, isn't it? This is a "feature" of ccd. Vinum would handle this situation correctrly. > I tried removing the "unplugged" disk drive from the ccd.conf line, > effectively meaning that ccd0 had only 1 disk drive (the working > one). It didn't work, still wanted to fsck. That should have worked. You'll still need to reconfigure, which implies rebooting. Possibly you told ccd that it still had a mirror. > I still haven't brought myself to test the scenario of unplugging a > drive "hot", and seeing what happens :-) You'll crash the ccd. > I'm not getting a warm fuzzy feeling about this. Unless I can > figure out how to separate the ccd mirror, or run on 1 drive alone > for a short period of time, I think I just statistically have halved > the MTBF of either drive. And recovery from a drive failure as such > seems impossible. Agreed. > BTW, I've used Solstice on Solaris (please no flames) and it has > saved my bacon on a mirror failure. Otherwise, the FBSD ccd works > just fine. I just want to know what to do when it doesn't. Move to vinum. I don't see any advantage in ccd any more. Check out vinum(4), vinum(8) and http://www.lemis.com/vinum.html. Greg -- When replying to this message, please copy the original recipients. For more information, see http://www.lemis.com/questions.html Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message