From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: mdadm No md superblock detected Date: Mon, 2 Dec 2013 17:18:39 +1100 Message-ID: <20131202171839.125c378d@notabene.brown> References: <6A48F5BB-7F74-4898-9C25-BC8E5B05AB31@gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/1a0Z2YQN3VClAT+x.xZZBmT"; protocol="application/pgp-signature" Return-path: In-Reply-To: <6A48F5BB-7F74-4898-9C25-BC8E5B05AB31@gmail.com> Sender: linux-raid-owner@vger.kernel.org To: Teitur Ingi Sigurdsson Cc: david@dgreaves.com, linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/1a0Z2YQN3VClAT+x.xZZBmT Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Sat, 30 Nov 2013 02:33:24 +0000 Teitur Ingi Sigurdsson wrote: > Hi there >=20 > I tried sending to linux-raid@vger.kernel.org about 10 days ago but got n= o answer, your guys are probably just busy but incase you did not get the e= mail i=E2=80=99m sending it here as well. >=20 > Hi there and thanks for your service >=20 > I=E2=80=99m having a problem with my 4x 2tb raid 5 mdadm array. >=20 > After an unexpected shutdown my machine booted into dos busybox, when i t= yped exit I got the ubuntu(12.04) logo and a message telling me it could no= t mount my raid drive so I pressed S to skip it. >=20 > The first thing I did was to do a complete long test with seagate sea too= ls to check all my hard drives for errors and all the drives are ok. >=20 > I found out that 2 of my drives where not assembling into the array. >=20 > When I tried to assemble the array it told me on these two drives there w= ere no md superblocks detected. >=20 > I started googling around and trying to find a solution to the problem , = found lots of forums and people with similar problems, >=20 > When I tried : sudo mdadm =E2=80=94assemble =E2=80=94scan in the first pl= ace it responded that i had duplicate UUID in my mdadm config file. So I lo= oked at the config file and found these 2 UUID : > ARRAY /dev/md0 level=3Draid5 num-devices=3D3 UUID=3Df7783df2:bc896dcc:9c7= 29cd1:10366cce > ARRAY /dev/md0 level=3Draid5 num-devices=3D3 UUID=3D48877e00:48c5e221:9c7= 29cd1:10366cce >=20 > the weird thing here is that the number of devices here are 3 not 4 like = I have always been using, at least I=E2=80=99ve been using 4 2 tb drives to= get about 6 tb of space in an array in raid 5, not that it really matters = anyways, tried changing it but nothing happens when i execute the command := sudo mdadm =E2=80=94assemble =E2=80=94scan , don=E2=80=99t know why that i= s, maybe there is another config file I don=E2=80=99t know about >=20 > anyways=E2=80=99 i got this command from somebody with a similar problem = : sudo mdadm =E2=80=93examine =E2=80=93scan =E2=80=93config=3Dmdadm.conf >>= /etc/mdadm/mdadm.conf > and got some UUID copy-ed into my config file and tried the scan again bu= t it did not work. >=20 > I=E2=80=99ve tried so far : root@tserver:~# mdadm --create /dev/md0 --ver= bose --level=3D5 --raid-devices=3D4 /dev/sdd missing /dev/sdc missing=20 > and got this response: mdadm: layout defaults to left-symmetric > mdadm: layout defaults to left-symmetric > mdadm: chunk size defaults to 512K > mdadm: /dev/sdd appears to contain an ext2fs file system > size=3D1565576192K mtime=3DSat Nov 9 20:54:11 2013 > mdadm: /dev/sdd appears to be part of a raid array: > level=3Draid5 devices=3D4 ctime=3DTue Jan 11 00:26:47 2011 > mdadm: /dev/sdc appears to be part of a raid array: > level=3Draid5 devices=3D4 ctime=3DTue Jan 11 00:26:47 2011 > mdadm: size set to 1953382912K > Continue creating array? y > mdadm: Defaulting to version 1.2 metadata > mdadm: RUN_ARRAY failed: Input/output error >=20 > i was afraid that the create command could erase my data but some people = in the same position suggested it was okay. >=20 > I=E2=80=99ve tried the UUID assemble command and nothing happens : mdadm = --assemble /dev/md# --uuid=3D >=20 > here is my mdadm =E2=80=94examine :=20 > root@tserver:~# mdadm --examine /dev/sda > mdadm: No md superblock detected on /dev/sda. > root@tserver:~# mdadm --examine /dev/sda1 > mdadm: cannot open /dev/sda1: No such file or directory > root@tserver:~# mdadm --examine /dev/sda > mdadm: No md superblock detected on /dev/sda. > root@tserver:~# mdadm --examine /dev/sdc > /dev/sdc: > Magic : a92b4efc > Version : 1.2 > Feature Map : 0x0 > Array UUID : 3e74cf9b:b49ecf15:98722946:b19b30b6 > Name : tserver:0 (local to host tserver) > Creation Time : Mon Nov 18 23:05:33 2013 > Raid Level : raid5 > Raid Devices : 4 >=20 > Avail Dev Size : 3906767024 (1862.89 GiB 2000.26 GB) > Array Size : 5860148736 (5588.67 GiB 6000.79 GB) > Used Dev Size : 3906765824 (1862.89 GiB 2000.26 GB) > Data Offset : 262144 sectors > Super Offset : 8 sectors > State : clean > Device UUID : 3c5cb8d9:072a09df:72a9bf89:fa579762 >=20 > Update Time : Mon Nov 18 23:05:33 2013 > Checksum : 1fe51ccc - correct > Events : 0 >=20 > Layout : left-symmetric > Chunk Size : 512K >=20 > Device Role : Active device 2 > Array State : A.A. ('A' =3D=3D active, '.' =3D=3D missing) > root@tserver:~# mdadm --examine /dev/sdd > /dev/sdd: > Magic : a92b4efc > Version : 1.2 > Feature Map : 0x0 > Array UUID : 3e74cf9b:b49ecf15:98722946:b19b30b6 > Name : tserver:0 (local to host tserver) > Creation Time : Mon Nov 18 23:05:33 2013 > Raid Level : raid5 > Raid Devices : 4 >=20 > Avail Dev Size : 3906767024 (1862.89 GiB 2000.26 GB) > Array Size : 5860148736 (5588.67 GiB 6000.79 GB) > Used Dev Size : 3906765824 (1862.89 GiB 2000.26 GB) > Data Offset : 262144 sectors > Super Offset : 8 sectors > State : clean > Device UUID : 9a96576f:4fba1e25:7077591b:c9987f29 >=20 > Update Time : Mon Nov 18 23:05:33 2013 > Checksum : 541bf63b - correct > Events : 0 >=20 > Layout : left-symmetric > Chunk Size : 512K >=20 > Device Role : Active device 0 > Array State : A.A. ('A' =3D=3D active, '.' =3D=3D missing) > root@tserver:~# mdadm --examine /dev/sde > mdadm: No md superblock detected on /dev/sde. >=20 >=20 > and sudo fdisk -l :=20 > sudo fdisk -l >=20 >=20 > Disk /dev/sda: 2000.4 GB, 2000397852160 bytes > 255 heads, 63 sectors/track, 243201 cylinders, total 3907027055 sectors > Units =3D sectors of 1 * 512 =3D 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disk identifier: 0x00000000 >=20 > Disk /dev/sda doesn't contain a valid partition table >=20 > Disk /dev/sdc: 2000.4 GB, 2000398934016 bytes > 255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors > Units =3D sectors of 1 * 512 =3D 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disk identifier: 0x00000000 >=20 > Disk /dev/sdc doesn't contain a valid partition table >=20 > Disk /dev/sde: 2000.4 GB, 2000397852160 bytes > 255 heads, 63 sectors/track, 243201 cylinders, total 3907027055 sectors > Units =3D sectors of 1 * 512 =3D 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disk identifier: 0x00000000 >=20 > Disk /dev/sde doesn't contain a valid partition table >=20 > Disk /dev/sdd: 2000.4 GB, 2000398934016 bytes > 255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors > Units =3D sectors of 1 * 512 =3D 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disk identifier: 0x00000000 >=20 > Disk /dev/sdd doesn't contain a valid partition table >=20 > Disk /dev/sdb: 500.1 GB, 500107862016 bytes > 255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors > Units =3D sectors of 1 * 512 =3D 512 bytes > Sector size (logical/physical): 512 bytes / 512 bytes > I/O size (minimum/optimal): 512 bytes / 512 bytes > Disk identifier: 0x00026ec6 >=20 > Device Boot Start End Blocks Id System > /dev/sdb1 * 2048 937164799 468581376 83 Linux > /dev/sdb2 937166846 976771071 19802113 5 Extended > /dev/sdb5 937166848 976771071 19802112 82 Linux swap / Sola= ris >=20 >=20 > can you suggest anything? >=20 > My goal is to be able to re arrange my array without any data loss :) Unfortunately you seem to have made a mess of things. That --create command wasn't a very clever idea. You list 2 devices as 'missing' which of course cannot work with RAID5, so it is no surprise that it didn't work. At a guess I'd say that you originally create the array on partitions, and now you are working with the whole-disk devices, which just adds to the confusion. But maybe you used whole disks - I can't really tell. I think your only option at this point is to try --creating the array in various combinations with 3 devices and 1 'missing' and then look at the content (maybe with 'fsck -n') until you find something that works. Did you have any backups? :-( NeilBrown --Sig_/1a0Z2YQN3VClAT+x.xZZBmT Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIVAwUBUpwmPznsnt1WYoG5AQKHvg/+Mi+EvmXvmlsvCI1refqb4XQOXqq/ykm/ Bz/x9ZIkphx0YvEX+HVfmUA7O0Dxit7TaOXG3ofJhgPMFlCTVFO1zqcf3C2/MNhN hRAw1uJLA4mmrTbSryoVRfsWn9XqADN0keiqv2UAuBp+uaoJs7/Z+pvKqR26waox IMpWTGwjzuUhAaCfvQQpeC7ktiOzHxNS82VQF9864Z756H6Qi7E8kS8SgHybrWsw q+XP1BAmqPEjTclL0h0rXUl6jQByReAE6HIVi0IqPCD1TZ4uRkXUBPWqagSPgfRc dvnLt8W2joSqXbJo9Rwh3tsHJwUiLaQQB9ZIBCoyUavNrNrNqg5YhI1xl7JIhCul lMzA2NU2u7K7cmIKRKhhM11ak/faLl7DfDKMaRF2U2gn7K4NkNfsmrbjirBzLioK JGEqWhXEf2N6nHywSj0Cx+5VVEeL8rrK7D75KofyQwQEybc1p4c3QfU/IIxxMFuE B8zwTirI2JzEzqrZNOwEXn5TJe2AxXMWS9mV1uscFK6uhL/6yuoFQBNpihWmiyLe BkqGPaJC+T8rn/Q5L1qY/INSyV9R/jtHi4PSiUT7rudOrFtzEPXm1MN/Z6pR/9Q2 MFhSLpxdIfLMrwKCU48oBRmp/ReGFFSmKuSgUiAJOKXUDcwIaOfVm4e80QCuvFpG ZM5KlryLSHA= =OuhJ -----END PGP SIGNATURE----- --Sig_/1a0Z2YQN3VClAT+x.xZZBmT--