On Sat, 30 Nov 2013 02:33:24 +0000 Teitur Ingi Sigurdsson <teitso@xxxxxxxxx>
wrote:
> Hi there
>
> I tried sending to linux-raid@xxxxxxxxxxxxxxx about 10 days ago but got no answer, your guys are probably just busy but incase you did not get the email i’m sending it here as well.
>
> Hi there and thanks for your service
>
> I’m having a problem with my 4x 2tb raid 5 mdadm array.
>
> After an unexpected shutdown my machine booted into dos busybox, when i typed exit I got the ubuntu(12.04) logo and a message telling me it could not mount my raid drive so I pressed S to skip it.
>
> The first thing I did was to do a complete long test with seagate sea tools to check all my hard drives for errors and all the drives are ok.
>
> I found out that 2 of my drives where not assembling into the array.
>
> When I tried to assemble the array it told me on these two drives there were no md superblocks detected.
>
> I started googling around and trying to find a solution to the problem , found lots of forums and people with similar problems,
>
> When I tried : sudo mdadm —assemble —scan in the first place it responded that i had duplicate UUID in my mdadm config file. So I looked at the config file and found these 2 UUID :
> ARRAY /dev/md0 level=raid5 num-devices=3 UUID=f7783df2:bc896dcc:9c729cd1:10366cce
> ARRAY /dev/md0 level=raid5 num-devices=3 UUID=48877e00:48c5e221:9c729cd1:10366cce
>
> the weird thing here is that the number of devices here are 3 not 4 like I have always been using, at least I’ve 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 —assemble —scan , don’t know why that is, maybe there is another config file I don’t know about
>
> anyways’ i got this command from somebody with a similar problem : sudo mdadm –examine –scan –config=mdadm.conf >> /etc/mdadm/mdadm.conf
> and got some UUID copy-ed into my config file and tried the scan again but it did not work.
>
> I’ve tried so far : root@tserver:~# mdadm --create /dev/md0 --verbose --level=5 --raid-devices=4 /dev/sdd missing /dev/sdc missing
> 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=1565576192K mtime=Sat Nov 9 20:54:11 2013
> mdadm: /dev/sdd appears to be part of a raid array:
> level=raid5 devices=4 ctime=Tue Jan 11 00:26:47 2011
> mdadm: /dev/sdc appears to be part of a raid array:
> level=raid5 devices=4 ctime=Tue 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
>
> i was afraid that the create command could erase my data but some people in the same position suggested it was okay.
>
> I’ve tried the UUID assemble command and nothing happens : mdadm --assemble /dev/md# --uuid=<UUID>
>
> here is my mdadm —examine :
> 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
>
> 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
>
> Update Time : Mon Nov 18 23:05:33 2013
> Checksum : 1fe51ccc - correct
> Events : 0
>
> Layout : left-symmetric
> Chunk Size : 512K
>
> Device Role : Active device 2
> Array State : A.A. ('A' == active, '.' == 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
>
> 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
>
> Update Time : Mon Nov 18 23:05:33 2013
> Checksum : 541bf63b - correct
> Events : 0
>
> Layout : left-symmetric
> Chunk Size : 512K
>
> Device Role : Active device 0
> Array State : A.A. ('A' == active, '.' == missing)
> root@tserver:~# mdadm --examine /dev/sde
> mdadm: No md superblock detected on /dev/sde.
>
>
> and sudo fdisk -l :
> sudo fdisk -l
>
>
> Disk /dev/sda: 2000.4 GB, 2000397852160 bytes
> 255 heads, 63 sectors/track, 243201 cylinders, total 3907027055 sectors
> Units = sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disk identifier: 0x00000000
>
> Disk /dev/sda doesn't contain a valid partition table
>
> Disk /dev/sdc: 2000.4 GB, 2000398934016 bytes
> 255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
> Units = sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disk identifier: 0x00000000
>
> Disk /dev/sdc doesn't contain a valid partition table
>
> Disk /dev/sde: 2000.4 GB, 2000397852160 bytes
> 255 heads, 63 sectors/track, 243201 cylinders, total 3907027055 sectors
> Units = sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disk identifier: 0x00000000
>
> Disk /dev/sde doesn't contain a valid partition table
>
> Disk /dev/sdd: 2000.4 GB, 2000398934016 bytes
> 255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
> Units = sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disk identifier: 0x00000000
>
> Disk /dev/sdd doesn't contain a valid partition table
>
> Disk /dev/sdb: 500.1 GB, 500107862016 bytes
> 255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
> Units = sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disk identifier: 0x00026ec6
>
> 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 / Solaris
>
>
> can you suggest anything?
>
> 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
Attachment:
signature.asc
Description: PGP signature
