From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: Converting from Raid 5 to 6 Date: Mon, 2 Dec 2013 16:51:27 +1100 Message-ID: <20131202165127.0fe2dd5f@notabene.brown> References: <20111025071443.4c497656@notabene.brown> <20111025073908.6d754588@notabene.brown> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/G.Ewr1yGHQEJXTnof.8IrNF"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Michael Busby Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/G.Ewr1yGHQEJXTnof.8IrNF Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Sat, 30 Nov 2013 22:13:58 +0000 Michael Busby wrote: > Sorry to bring up a old thread, last night i had a power cut and this > morning when the power has come back i have tried to boot the server, > but the raid will not assemble on using a live CD i have found that > one of the disk is reporting "possibly out of date" is there any way > to force this disk back in? the bigger problem i have is that my > external caddie has died so i was running a degraded raid 6 but now it > is only starting with 4 out of 6 devices. is there anyway to get this > back? It's really hard to know what is possible without precise details. Output of "mdadm -E" for each member device is always a good idea. If you are having trouble assembling, then output of the assemble command with -vv added never goes astray. Have you tried adding "-f" to the assemble command. Often helps and is unlikely to hurt. >=20 > i have though about recreating the array using the --assume-clean > option but not sure if that's a good idea Not a good idea except as a very last resort. NeilBrown >=20 > any help will be much appreciated >=20 >=20 >=20 > On 24 October 2011 21:47, Michael Busby wrote: > > > > I was sure i added the device before, but when rebooted the system it > > has seemed to lose the extra drive and i had already restarted the > > grow command with out checking the disk was there, so more than likely > > a mistake by me > > > > > > > > On 24 October 2011 21:39, NeilBrown wrote: > > > On Mon, 24 Oct 2011 21:19:22 +0100 Michael Busby > > > wrote: > > > > > >> Ok thanks, i have 1 small issue, when added the extra disk its been > > >> maked as spare, is this normal? > > >> > > >> Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] > > >> [raid4] [raid10] > > >> md0 : active raid6 sde[0] sdg[6](S) sda[4] sdb[3] sdd[2] sdc[1] > > >> 7814055936 blocks super 1.0 level 6, 512k chunk, algorithm 18 > > >> [6/5] [UUUUU_] > > >> [>....................] reshape =3D 3.0% (59244544/195351398= 4) > > >> finish=3D11122.8min speed=3D2837K/sec > > >> > > > > > > It looks like the extra drive was added after you started the grow. > > > > > > So it is still a spare. > > > Once the grow finishes you will have a singly-degraded RAID6. > > > Then it will immediately start recovering the missing device to the s= pare. > > > > > > Did you add the extra drive after starting the grow - or before?? > > > > > > NeilBrown > > > > > > > > > > > > > > > >> > > >> > > >> > > >> On 24 October 2011 21:14, NeilBrown wrote: > > >> > On Mon, 24 Oct 2011 17:03:46 +0100 Michael Busby > > >> > wrote: > > >> > > > >> >> should the speed be very slow when doing this progress, its a lot > > >> >> slower than a normal grow > > >> > > > >> > Yes. > > >> > The array is being reshaped in-place. i.e. data is being read fro= m part of > > >> > the array, rearranged, and written back to the same part of the ar= ray. > > >> > As you can imagine, this is risky - a crash will leave an inconsis= tent state. > > >> > Hence the backup file. Everything in the array is first written t= o the > > >> > backup file, then back to the array. So it is slow. > > >> > > > >> > A "normal" grow is writing to somewhere where there is no valid da= ta, so it > > >> > doesn't need the backup. > > >> > > > >> > I do have a plan to make this faster.... but I have lots of plans = and little > > >> > time. > > >> > > > >> > NeilBrown > > >> > > > >> > > > >> > > > >> > > > >> >> > > >> >> reshape =3D 1.2% (25006080/1953513984) finish=3D12481.8min speed= =3D2574K/sec > > >> >> > > >> >> On 24 October 2011 15:11, Mathias Bur=C3=A9n wrote: > > >> >> > On 24 October 2011 14:11, Michael Busby wrote: > > >> >> >> At the moment i have a raid5 setup with 5 disks, i am looking = to add a > > >> >> >> 6th disk and change from raid 5 to raid 6 > > >> >> >> > > >> >> >> having looked at Neil's site i have found the following comman= d, and > > >> >> >> just want to double check this is still the recommend way of > > >> >> >> converting > > >> >> >> > > >> >> >> mdadm --grow /dev/md0 --level=3D6 --raid-disks=3D6 --backup-fi= le=3D/home/md.backup > > >> >> >> > > >> >> >> also would i need to add the extra disk before or after the co= mmand? > > >> >> >> > > >> >> >> cheers > > >> >> >> -- > > >> >> >> To unsubscribe from this list: send the line "unsubscribe linu= x-raid" in > > >> >> >> the body of a message to majordomo@vger.kernel.org > > >> >> >> More majordomo info at http://vger.kernel.org/majordomo-info.= html > > >> >> >> > > >> >> > > > >> >> > Hi, > > >> >> > > > >> >> > I grew my 6 disk RAID5 to a 7 disk RAID6. First, add the drive.= Then > > >> >> > partition it as required. Then add the drive to the array (I th= ink > > >> >> > it'll become a spare?). Then you can grow it. > > >> >> > > > >> >> > Make sure you're using the latest mdadm tools available. > > >> >> > > > >> >> > Regards, > > >> >> > Mathias > > >> >> > > > >> >> -- > > >> >> To unsubscribe from this list: send the line "unsubscribe linux-r= aid" in > > >> >> the body of a message to majordomo@vger.kernel.org > > >> >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > >> > > > >> > > > > > > > --Sig_/G.Ewr1yGHQEJXTnof.8IrNF Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIVAwUBUpwf3znsnt1WYoG5AQIGLA//S5qg1OtGUdvjb2V7wCbkRr4YZ3+9HtHM aKTiP/qfqCy44pPf1BkZ85SjmZ8CVdGdy9vAzsKlSWv2rYydgEARxJ5TfSBmoYZB 6sWCiQZyom4BVUcWH8g/zrgJmMF3gy/4nTBUG7P4nfHHGCrByV12e9R0yh4Iib3C QEHeg+PjjaPqfahVPPyp+mYuhzm3GMvk4ntqn3vDw4ycmP3ju/fUEtaA+cQS9oUT jr6kM/cPhG1iOVQ4u81vqxNVd3a4b4mvxQC4Qjt25IzzP3RD39BOJ0DRC0dAwu9H tdXNE11xBEWqQvGc5etHZiy25DYdr88E1GwyL6JQzeu4gvmnJnM23WvhOYg4l2tC R4XWIVCyVy4MSLIdg9GbAqyRhG6FWE5r7i/NocKKUirN1c04GgJ1QkmXRAmgU0GW j/A71uz23zsQ8V9RrYE5oHgzhP71FBqEqod3YF0PaV/bt0lW7M2g9ObYZclVWBAa 9/Q/fBT/BMhFk9ST5NT77BabfcydaN2N5vf7QDeqsQQrDIHga8AImlDfpJxwCstc XFLr06cwMEJApT7FbWYmhF+EI10jVsFyIX9fpyJSlShqm3zAOJpP40u4+mTGEQ2r 7A3B4cNxTckgtsRtCQxtB8PDqzmLIrG9f6wR6huTM0rpGQBA+KPcBnmAOHJwarr5 rXNWacNuocQ= =g/3L -----END PGP SIGNATURE----- --Sig_/G.Ewr1yGHQEJXTnof.8IrNF--