Raid 5 EXT4-fs (md0): VFS: Can't find ext4 filesystem

[john410312]

My Raid 5 (4x3TB) was running degraded and before I was able to replace the failed HD, an Ubuntu kernel upgrade fried the raid. Not being able to rebuild the arrray, I zeroed the superblock and recreated. Probably my first mistake. I was able to get the array to resync and become clean but still am unable to mount due to...

Code: Select all

john@nasmedia:~$ sudo mount -a 
mount: wrong fs type, bad option, bad superblock on /dev/md0, 
       missing codepage or helper program, or other error 
       In some cases useful info is found in syslog - try 
       dmesg | tail  or so 

john@nasmedia:~$ dmesg | tail 
[  616.187924] EXT4-fs (md0): VFS: Can't find ext4 filesystem 

fdisk responds

Code: Select all

Disk /dev/md0: 9001.4 GB, 9001370124288 bytes 
2 heads, 4 sectors/track, -2097367168 cylinders, total 17580801024 sectors 
Units = sectors of 1 * 512 = 512 bytes 
Sector size (logical/physical): 512 bytes / 4096 bytes 
I/O size (minimum/optimal): 524288 bytes / 1572864 bytes 
Disk identifier: 0x00000000 

Disk /dev/md0 doesn't contain a valid partition table 

Testdisk /dev/md0 responds

Code: Select all

TestDisk 6.14, Data Recovery Utility, July 2013
Christophe GRENIER <grenier@cgsecurity.org>
http://www.cgsecurity.org

Disk /dev/md0 - 9001 GB / 8383 GiB - CHS 2197600128 2 4
Current partition structure:
     Partition                  Start        End    Size in sectors

Bad GPT partition, invalid signature.
Trying alternate GPT
Bad GPT partition, invalid signature.

A deep search gives me some MS partitions but they are for a 6001GB build that was what the Raid was before when it was a 3x3TB Raid. Pressing L to list files brings up nothing.

See also viewtopic.php?f=7&t=6824

Not sure where to go now.