From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Robinson Subject: Re: Check/repair RAID-5 with hints? Date: Sat, 03 Apr 2010 02:06:38 +0100 Message-ID: <4BB6949E.2020205@anonymous.org.uk> References: <4BB5D9B1.8070000@anonymous.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4BB5D9B1.8070000@anonymous.org.uk> Sender: linux-raid-owner@vger.kernel.org To: Linux RAID List-Id: linux-raid.ids On 02/04/2010 12:49, John Robinson wrote: > I have just replaced one of the drives in my RAID-5 array which was > showing offline uncorrectable and current pending sectors. I took the > system down into single-user mode, failed the disc out of the array, > dd_rescue'd the disc to a fresh one, and added the new disc back into > the array. During the dd_rescue, 68k of 1TB failed, about 1MB from the > end of the disc. My array has a write-intent bitmap so the resync was > very quick. So now I have an active, theoretically synchronised RAID-5, > and I know some 68k on one of the discs is likely rubbish. Turns out not to be a problem. I ran a check>/sys/block/md1/md/sync_action and got no mismatches, which I guess means there isn't a problem. This probably means it was an unused portion of the disc so 00 ^ 00 == 00 or whatever. I'd still be interested in a solution to this in case something similar comes up again. Cheers, John.