From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Collette Subject: Re: mdadm create to existing raid5 Date: Fri, 13 Jul 2007 11:25:20 -0700 Message-ID: <4697C390.8000501@etelos.com> References: <200707122318.l6CNIao08247@www.watkins-home.com> <469736E2.7040802@dgreaves.com> <469754B0.4020104@dgreaves.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <469754B0.4020104@dgreaves.com> Sender: linux-raid-owner@vger.kernel.org To: David Greaves Cc: Guy Watkins , linux-raid@vger.kernel.org List-Id: linux-raid.ids The mdadm --create with missing instead of a drive is a good idea. Do you actually say missing or just leave out a drive? However doesn't it do a sync everytime you create? So wouldn't you run the risk of corrupting another drive each time? Or does it not sync because of the saying missing? To bad I am intent on learning things the hard way. /etc/mdadm.conf from before I recreated ARRAY /dev/md2 level=raid5 num-devices=4 spares=1 UUID=4f935928:2b7a1633:71d575d6:dab4d6bc /etc/mdadm.conf after I recreated ARRAY /dev/md1 level=raid5 num-devices=4 UUID=81bdd737:901c0a8f:af38cb94:41c4e3da Well before I heard back from you guys . I noticed this problem and in my fountain of infinite wisdom I did mdadm --zero-superblock to all my raid drives and created them again thinking if I got it to look the same it woud just fix it. Well they do look the same now, I am at work or I would give you the new mdadm.conf. I really need to learn patients :( David Greaves wrote: > David Greaves wrote: >> For a simple 4 device array I there are 24 permutations - doable by >> hand, if you have 5 devices then it's 120, 6 is 720 - getting tricky ;) > > Oh, wait, for 4 devices there are 24 permutations - and you need to do > it 4 times, substituting 'missing' for each device - so 96 trials. > > 4320 trials for a 6 device array. > > Hmm. I've got a 7 device raid 6 - I think I'll go an make a note of > how it's put together... > > > Have a look at this section and the linked script. > I can't test it until later > > http://linux-raid.osdl.org/index.php/RAID_Recovery > > http://linux-raid.osdl.org/index.php/Permute_array.pl > > > David > > > - > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html