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 :)
Thanks for reading
Best Regards
Teitur--
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