PLEASE HELP!!! RAID problems with 10.04

Bazooka Joe fastfish at
Mon Apr 12 18:17:46 UTC 2010

Try using testdisk installed via synaptic and see what it can see.

On Mon, Apr 12, 2010 at 9:11 AM, Alvin Thompson <alvin at> wrote:
> Sorry about the repost, but can anyone please help me with this?  I really need the data on this drive.  I'm pretty sure the install altered the partition where the RAID drive resides, but I don't know how to fix it.  Can anyone please help?
> I tried installing 10.04 server on a system and now my RAID5 data device is corrupted.  I did not tell the installer to do anything to my RAID device when I was installing, but I did tell the installer to create other RAID5 devices from other partitions on the same drives.  I have a lot of very important data on that device so any suggestions would be appreciated.  Can anyone please help, or does anyone have any idea on how to fix?
> First, this was my original setup.  I had 4 500GB drives (sda-sdd), each with identical partition tables:
>  sd[abcd]1:  25GB
>  sd[abcd]2: 475GB    RAID5
> My RAID5 device was /dev/md1 and consisted of partition 2 on all drives (4 active, no spares):
>  md1 = sd[abcd]2    1.2TB    formatted as XFS
> My previous linux install was on sda1 (25GB, no RAID).  The remaining partitions (sd[bcd]1) were unused in my old setup.
> Everything was working fine before I attempted to install Ubuntu.
> I decided to do a clean install of 10.04 to take advantage of grub2 booting straight to a RAID5 partition.  I specified manual partitioning, removed partition 1 on all drives (leaving partition 2 alone), and set up partitions/RAID as follows:
>  --added partitions and RAID devices--
>  sd[abcd]1:  22GB    RAID5    md2    /
>  sd[abcd]3:   3GB    RAID5    md3    (swap)
>  --original, untouched RAID device--
>  sd[abcd]2: 475GB    RAID5    md1    (not mounted)
> I did not touch md1 or partition 2 on any drive (my original RAID device), but when I chose to write changes to disk, the installer listed partition 2 as one of the partitions to be modified on the drives.  I did NOT want partition 2 to be modified so I backed out of all changes and redid them, making doubly sure that I did not modify partition 2 or md1.  The partitioner still listed partition 2 as one of the partitions to be modified, and this time I agreed, assuming since I hadn't actually changed anything there would be no problems (my mistake).
> Now that the install is complete, as you can guess, md1 is not working, but md2 and md3 (created during the install) are.  I'm assuming the layout for partition 2 was indeed modified, so how do I fix it?  The way I see it, there are 2 very serious bugs here:
> 1. The installer modified partitions without the user expressly telling it to do so.
> 2. The installer modified partitions that were already used by a RAID device.  Partitions should NEVER EVER be modified until any raid devices that use them are removed, even if the installer did not create the RAID device.
> Can anyone please help?
> Thanks,
> Alvin
> some possibly relevant output:
> alvin at io:~$ sudo mount -t xfs /dev/md1 /data/
> mount: wrong fs type, bad option, bad superblock on /dev/md1,
>      missing codepage or helper program, or other error
>      In some cases useful info is found in syslog - try
>      dmesg | tail  or so
> alvin at io:~$ sudo xfs_check /dev/md1
> xfs_check: /dev/md1 is not a valid XFS filesystem (unexpected SB magic number 0x00000000)
> xfs_check: WARNING - filesystem uses v1 dirs,limited functionality provided.
> xfs_check: read failed: Invalid argument
> xfs_check: data size check failed
> cache_node_purge: refcount was 1, not zero (node=0x1eba990)
> xfs_check: cannot read root inode (22)
> bad superblock magic number 0, giving up
> alvin at io:~$ sudo cat /proc/mdstat
> Personalities : [raid6] [raid5] [raid4] [linear] [multipath] [raid0] [raid1] [raid10]
> md1 : active raid5 sdc2[2] sda2[0] sdd2[3] sdb2[1]
>     1391919552 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
> md3 : active raid5 sdd3[3] sdc3[2] sda3[0] sdb3[1]
>     8776512 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
> md2 : active raid5 sdd1[3] sda1[0] sdc1[2] sdb1[1]
>     64450368 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
> unused devices: <none>
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