From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wols Lists Subject: Re: Linux raid wiki Date: Mon, 26 Sep 2016 22:37:49 +0100 Message-ID: <57E9952D.6020703@youngman.org.uk> References: <57E469E0.4020005@youngman.org.uk> <57E67D32.30108@youngman.org.uk> <57E95054.4020903@youngman.org.uk> <33ee0032-11a7-3637-170a-a9da94c7bda9@turmel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <33ee0032-11a7-3637-170a-a9da94c7bda9@turmel.org> Sender: linux-raid-owner@vger.kernel.org To: Phil Turmel , linux-raid@vger.kernel.org List-Id: linux-raid.ids On 26/09/16 22:19, Phil Turmel wrote: > On 09/26/2016 12:44 PM, Wols Lists wrote: >> The next section - >> >> https://raid.wiki.kernel.org/index.php/Assemble_Run >> >> addresses what to do if the array is messed up in some way. Would you >> mind taking a look at that now too :-) > > Hmmm. The last bit is less than ideal. If all drives are faulty, but > runnable in the array with at least one drive of redundancy, the best > way to put good drives in service is one-by-one mdadm --replace. That > lets the redundancy fix any errors, and doesn't load down the problem > drive any more than ddrescue would. And it has the benefit of > increasing reliability as you go. > > If you don't have any redundancy left, then ddrescue of all readable > drives is reasonable. > Which is the state this page is meant to cover. I'm assuming that if you get this far, you have at an absolute minimum had to have done a "--force --assemble" just to get a working array. Each page has been intended to successively cover the state of the array getting worse. The next page is "my metadata is trashed - mdadm says the drive doesn't exist". I'm really not sure how to tackle that, but I know there are several threads which cover damaged or trashed superblocks. I think I'll just have to say "this is how you track down a GPT. This is how you track down a superblock. This is how you interpret it. Get the experts to help you put the array together again." Cheers, Wol