From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Urlichs Subject: raid6 recovery with read errors Date: Mon, 3 Aug 2009 08:36:06 +0000 (UTC) Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi, I have a rather large RAID6 array where multiple disks have developed read errors. The problem is that the RAID6 is built from LVM-mapped disks, which (I think) isolated the MD driver from write errors. Thus it thought that a re-write of the bad sectors succeeded. WRONG. Thus the bad disks were never unmapped. The problem is that yesterday, three of these TByte disks failed in _exactly_ the same 1k-sized spot. So, no more RAID6. :-( So, how do I get the data back? I've copied the individual partitions with ddrescue, which conveniently left me a log file pointing to the sectors which need to be recovered. However, I'm sure that there's no way to tell the kernel about individual "bad spots". Is there a standalone program that can do that? -- Matthias Urlichs