From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Arthur Oehser Subject: Re: Is shrinking raid5 possible? Date: Fri, 6 Nov 2009 13:38:46 -0500 Message-ID: <20091106183845.GB13412@Toms.NET> References: <44960C45.9050407@anu.edu.au> <17558.10906.59066.196870@cse.unsw.edu.au> <449B3A80.4070602@tmr.com> <17563.17224.85968.572754@cse.unsw.edu.au> <17567.36792.303403.35943@cse.unsw.edu.au> <4564B5C3.9050501@idgmail.se> <20091106131740.GA30506@Toms.NET> <4AF46BAF.3020900@anonymous.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4AF46BAF.3020900@anonymous.org.uk> Sender: linux-raid-owner@vger.kernel.org To: John Robinson Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Fri, Nov 06, 2009 at 06:32:15PM +0000, John Robinson wrote: > On 06/11/2009 13:17, Thomas Arthur Oehser wrote: > [...] >> - resize2fs /dev/md3 >> - mdadm -G -z /dev/md3 >> - fdisk /dev/sd[a-c]3 >> >> It _almost_ works fine... but... the mdadm -G keeps the (0.90) superblock >> at the _end_ of the _device_ ... which hasn't been resized yet ... >> >> How do I put the superblock back after fdisk, or make -G move or recreate? > > Are you sure it hasn't already put a copy of the superblock in the right > place, within the size, as well as leaving a copy at the end > of the original larger partition? That's what I would do if I was the > author, so the partition can still be recognised as a md one before the > partition is resized; you wouldn't want the parition to become > unrecognisable or unusable. Far as I can tell, no, because when I then shrink the partition, it can't find the superblock.