From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Schinagl Subject: Small short question Was: Re: Recovering from the kernel bug, Neil? Date: Fri, 14 Sep 2012 13:51:46 +0200 Message-ID: <50531A52.7060205@schinagl.nl> References: <5030F07F.7000303@schinagl.nl> <504CFA7B.7090606@schinagl.nl> <20120910090829.19100cdf@notabene.brown> <504DA85C.6080000@schinagl.nl> <20120911161622.0b0fcf8c@notabene.brown> <505301E1.10707@schinagl.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <505301E1.10707@schinagl.nl> Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Since I had only one valid device to check with etc, I assume that if fsck -n -f /dev/md2 runs sucessfully, it is 100% safe to assume the array is perfectly healthy? E.g. it should be perfectly safe to mdadm --zero-superblock on /dev/sda6 and add it to /dev/md2 (missing /dev/sdb6)? I know technically this all works out fine, and the bug shouldn't have broken anything in that regard. Or is it absolutly recommended to simply create a new array, with a new FS on it, and copy all data over (Logically also with /dev/md2, /dev/sda6 missing and later adding sdb6)? Oliver On 09/14/12 12:07, Oliver Schinagl wrote: > So I've spent the last few days trying several things to recover the > array. Assumption is the mother right? > > I had 3 arrays, /, /usr and /opt. I did some basic research at the > various raid levels, and for some reason decided that f2 was good for /, > and o2 for /usr. In that same trend I thought o2 was good for /opt as > well. I was wrong. I was so sure I made it o2, that I ruled out the > possibility it being f2. I did try various offsets, but never f2 with > missing /dev/sdb6. I think i even tried f2 in the passed, but on sda6 > where i may have broke things. > > Short story short, it turns out it was 128k chunks, Far2 offset. The > data actually is accessible from a dd-ed image looped to mdadm and that > mounted. I will now recreate my md2 array, and copy the data over. > > Thank you for all advice and help in the past and again. You are an > amazing dev and a good person. > > Oliver >