I had a raid 1 working with two devices sdc1 and sdd1, 2TB each. I needed some space, so I decided to undo the raid. I must say I'm too new with raids, and I successfully removed sdc1 with "fail" and "remove" mdadm commands, but not with sdd1, so I left the raid working and mounted the filesystem as follows:
/dev/sdc1 -> /data
/dev/md0 -> /data2
But a few days ago this "workaround" end up with a very bad and serious message forcing the server a reboot and rescue mode working.
I successfully removed the raid and mounted /dev/sdc1 into /data, but when I try to mount sdd1 into /data2 I get:
mount: you must specify the filesystem type
So, I exec:
mount -t ext4 /dev/sdd1 /data2
And I get the same error message. I tried with ext2 and ext3, but had the same result.
I also get this on dmesg:
VFS: Can't find ext3 filesystem on dev sdd1.
When I execute "fsck /dev/sdd1" I get the following:
fsck 1.39 (29-May-2006)
e2fsck 1.39 (29-May-2006)
Couldn't find ext2 superblock, trying backup blocks...
fsck.ext3: Bad magic number in super-block while trying to open /dev/sdd1
The superblock could not be read or does not describe a correct ext2
filesystem. *If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
* * e2fsck -b 8193 <device>
"fdisk -l /dev/sdd" reveals the following:
WARNING: GPT (GUID Partition Table) detected on '/dev/sdd'! The util fdisk doesn't support GPT. Use GNU Parted.
Disco /dev/sdd: 2000.3 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Unidades = cilindros de 16065 * 512 = 8225280 bytes
Device Begin End Blocks Id System
/dev/sdd1 1 243201 1953512032 83 Linux
I successfully executed "mdadm --zero-superblock /dev/sdd1", but I got "mdadm: Unrecognised md component device - /dev/sdd1"
I tried everything my expertise could, but with no positive results.
Please, note that sdc1 and sdd1 have now different data, so I can't create a new raid 1 and put these disks into this raid.