From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: RAID5 demise or coma? after re-creating with a spare Date: Sat, 5 Dec 2009 08:12:31 +1100 Message-ID: <20091205081231.22625302@notabene.brown> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Lucian =?UTF-8?B?yJhhbmRvcg==?= Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Fri, 4 Dec 2009 14:46:39 -0500 Lucian =C8=98andor wrote: > Hi all, > There is a problem with my Linux installation, and the drives get > renamed and reordered all the time. Now, it just happened that the tw= o > degraded RAID5s won't return to life. The system would not boot, so I > panicked and deleted: fstab, mdadm.conf, and some of the superblocks. > Now Linux boots, but RAIDs are, of course, dead. I tried to re-create > the arrays, but I cannot recall the correct order and my attempts > failed. I believe that the partitions are OK, because I don't recall > re-creating without "missing", but surely the superblocks are damaged > and certanily most of them are zero now. > Is there a short way to recover the degraded RAIDs without knowing th= e > order of drives? I have 6 drives in one (including "missing"), that > gives 720 permutations. Also, clearing the superblocks is recoverable= , > isn't it? Yes, 720 permutations. But you can probably write a script to generate them all ... how good are your programming skills? Use "--assume-clean" to create the array so that it doesn't auto-resync. Then "fsck -n" to see of the data is even close to correct. And why would you think that erasing the superblocks is a recoverable operation? It isn't. NeilBrown -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html