From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: raid 5 to raid 6 reshape gone bad Date: Sun, 13 Nov 2011 14:35:04 +1100 Message-ID: <20111113143504.7b1f75b1@notabene.brown> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/1H2Jvc5h01aa6mtkyCrlhRf"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Travis Brown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/1H2Jvc5h01aa6mtkyCrlhRf Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Sat, 12 Nov 2011 21:56:56 -0500 Travis Brown wrote: > I was reshaping my 5 drive raid 5 with spare to a raid 6 array when the d= rive I was using for my backup went offline. If that's not murphy's law, I= don't know what is. The array is still up and usable, but I'm afraid to r= eboot or doing anything to it, really. Suggestions on getting this thing b= ack to usable are very welcome.=20 >=20 > Thanks, > Travis >=20 > Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [rai= d4] [raid10]=20 > md126 : active raid6 sde3[0] sdf3[3] sdb3[1] sdd3[4] sdc3[2] > 5856728064 blocks super 0.91 level 6, 512k chunk, algorithm 18 [5/4= ] [UUUU_] > [>....................] reshape =3D 0.9% (19267584/1952242688) fi= nish=3D623878.3min speed=3D51K/sec 1/ Don't Panic. =20 You seem to have achieved this step quite effectively - congratulations. 2/ Stop the array cleanly. Not having a backup will only cause possible corruption if the machine crashes while the reshape is happening. The reshape has stopped so there is no chance for corruption. But you still need to cleanly stop the array. (A subsequent version of mdadm may allow you to continue the reshape without the stop/restart step, but we aren't there yet). 3/ Make sure you have a version of mdadm which is at least 3.2. I would suggest the latest:3.2.2. You particularly need the --invalid-backup flag. 4/ Reassemble the array with e.g. mdadm --assemble /dev/md126 --backup=3D/some/file \ --invalid-backup /dev/sd[bcdef]3 The backup file does not need to exist (I think). Maybe create an empty file and use that just to be safe. The "--invalid-backup" flag says to mdadm "Yes, I know the backup file is currently invalid and you cannot restore anything from it. I happen to know that there is no need to restore anything because I did a clean shutdown. Just use the backup file for making new backups as you contin= ue the reshape". NeilBrown >=20 > /dev/md126: > Version : 0.91 > Creation Time : Wed Nov 10 20:19:03 2010 > Raid Level : raid6 > Array Size : 5856728064 (5585.41 GiB 5997.29 GB) > Used Dev Size : 1952242688 (1861.80 GiB 1999.10 GB) > Raid Devices : 5 > Total Devices : 5 > Preferred Minor : 126 > Persistence : Superblock is persistent >=20 > Update Time : Sat Nov 12 21:55:46 2011 > State : clean, degraded, recovering > Active Devices : 4 > Working Devices : 5 > Failed Devices : 0 > Spare Devices : 1 >=20 > Layout : left-symmetric-6 > Chunk Size : 512K >=20 > Reshape Status : 0% complete > New Layout : left-symmetric >=20 > UUID : 3fd8b303:7727aa3b:c5d110f2:f9137e1d > Events : 0.124051 >=20 > Number Major Minor RaidDevice State > 0 8 67 0 active sync /dev/sde3 > 1 8 19 1 active sync /dev/sdb3 > 2 8 35 2 active sync /dev/sdc3 > 3 8 83 3 active sync /dev/sdf3 > 4 8 51 4 spare rebuilding /dev/sdd3-- > 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 --Sig_/1H2Jvc5h01aa6mtkyCrlhRf Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIUAwUBTr867jnsnt1WYoG5AQJ7lg/1GBv+Nh+XgsOxY4yP/r1NAVkqfaacGMoP CvfpUO/i/4d1ss1FZutwKZS15m96cr6kuGvbqyLI8HOOGvdumUFleCkXDEKiNsWs jf0RAAGX/YFzctSELlkr4tfwNePF/jP18zeaSkjE2TT/4zf11fmeDyEjXhu0F9u9 P46B9sP5d89nlFqMEA6Oa6YTF2Dtcj+YN04a9bv6hKTMAIc9l23oYOTyYojWt97a bvhJz2mY+C096adYrCaz7zru53qWImI9H4HNq9yKhanOSW+XC068AFo+LqVoqPH0 WTvKOtvPrTEkVkQsSkg9x8Qet/QYVVO9E+opgg3p3MjXgpbl783ZDN/aH0hF5+xN LOLgclm4hdpDGB2Ut1OzOUFv1422H8bJ76Vrb+DBg7XLUNK6rYL0RoZQyUCoSgai 6rZeNopAHpmJT6VAUBDgNe9Q08TPnGTk42Wt6Msoq2d4t0nnLgoX6vWmud2hpU3S 5bIXMejcnBstTUKW+gFXS2NbLeapSbQVX62722F6qh+WqVm26whFG+gqFsVCTEeg PpArQyuDe0NhK/G+yeglOzzHDDv4rYxNDNLAE/ji+HXrir+4NrLTjh3Yv2cxWRzE NiR865wDj21v6RAkhDUys4OWNy6ww0A3MJTxRyMEUMwAL4w2+sruFyspXbfxM0zH FS1zkFCQJQ== =jX5c -----END PGP SIGNATURE----- --Sig_/1H2Jvc5h01aa6mtkyCrlhRf--