Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757759AbXFQR2T (ORCPT ); Sun, 17 Jun 2007 13:28:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754671AbXFQR2H (ORCPT ); Sun, 17 Jun 2007 13:28:07 -0400 Received: from twinlark.arctic.org ([207.29.250.54]:41403 "EHLO twinlark.arctic.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754309AbXFQR2F (ORCPT ); Sun, 17 Jun 2007 13:28:05 -0400 Date: Sun, 17 Jun 2007 10:28:02 -0700 (PDT) From: dean gaudet To: Wakko Warner cc: Neil Brown , david@lang.hm, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org Subject: Re: limits on raid In-Reply-To: <20070617132809.GB7806@animx.eu.org> Message-ID: References: <18034.479.256870.600360@notabene.brown> <18034.3676.477575.490448@notabene.brown> <20070616020320.GB2002@animx.eu.org> <18035.23867.576212.859440@notabene.brown> <20070616140857.GA4206@animx.eu.org> <20070617132809.GB7806@animx.eu.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1818 Lines: 47 On Sun, 17 Jun 2007, Wakko Warner wrote: > dean gaudet wrote: > > On Sat, 16 Jun 2007, Wakko Warner wrote: > > > > > When I've had an unclean shutdown on one of my systems (10x 50gb raid5) it's > > > always slowed the system down when booting up. Quite significantly I must > > > say. I wait until I can login and change the rebuild max speed to slow it > > > down while I'm using it. But that is another thing. > > > > i use an external write-intent bitmap on a raid1 to avoid this... you > > could use internal bitmap but that slows down i/o too much for my tastes. > > i also use an external xfs journal for the same reason. 2 disk raid1 for > > root/journal/bitmap, N disk raid5 for bulk storage. no spindles in > > common. > > I must remember this if I have to rebuild the array. Although I'm > considering moving to a hardware raid solution when I upgrade my storage. you can do it without a rebuild -- that's in fact how i did it the first time. to add an external bitmap: mdadm --grow --bitmap /bitmapfile /dev/mdX plus add "bitmap=/bitmapfile" to mdadm.conf... as in: ARRAY /dev/md4 bitmap=/bitmap.md4 UUID=dbc3be0b:b5853930:a02e038c:13ba8cdc you can also easily move an ext3 journal to an external journal with tune2fs (see man page). if you use XFS it's a bit more of a challenge to convert from internal to external, but see this thread: http://marc.theaimsgroup.com/?l=linux-xfs&m=106929781232520&w=2 i found that i had to do "sb 1", "sb 2", ..., "sb N" for all sb rather than just the "sb 0" that email instructed me to do. -dean - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/