From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Small Subject: Re: faulty array member Date: Thu, 18 Nov 2010 19:29:18 +0000 Message-ID: <4CE57E8E.2040902@buttersideup.com> References: <4CE55D9E.4070406@supsi.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4CE55D9E.4070406@supsi.ch> Sender: linux-raid-owner@vger.kernel.org To: Roberto Nunnari Cc: "linux-raid@vger.kernel.org" List-Id: linux-raid.ids On 18/11/10 17:08, Roberto Nunnari wrote: > > md0 : active raid1 sdb1[1] sda2[2](F) > 40957568 blocks [2/1] [_U] > > The question is: > Is there a way and is it safe to put back /dev/sda2 into > /dev/md0 so that I'm sure I can backup even the blocks If there have been writes to md0 since sda2 was failed, then no. Your best best is probably to find out which sectors are bad in sdb1, and then copy those individual blocks (only) over from sda2 (e.g. using dd). Once sdb1 has no pending sectors left, you should then be able to re-add sda2 back into md0. I don't know what the bad-block remapping is like on the CentOS4 kernel, so you may want to use a more recent boot CD etc. to carry out the rebuild, if it doesn't work using the native kernel. Maybe. Tim.