TL;DR How to recover the
ext4file system from a corrupted RAID1 partition?
I have one failed disk that belonged to an RAID1 array on a Synology DiskStation, the other one is lost.
ddrescue I've copied most of the relevant data to a new disk.
The partition table survied, however some blocks essential to the RAID setup are corrupted.
# fdisk -l /dev/sdd Disk /dev/sdd: 3000.6 GB, 3000592982016 bytes 255 heads, 63 sectors/track, 364801 cylinders, total 5860533168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk identifier: 0x0003f44a Device Boot Start End Blocks Id System /dev/sdd1 256 4980735 2490240 fd Linux raid autodetect /dev/sdd2 4980736 9175039 2097152 fd Linux raid autodetect /dev/sdd3 9437184 3907024064 1948793440+ fd Linux raid autodetect
The actual data is on the third partition
mdadm can't assemble the array.
# mdadm --examine /dev/sdd /dev/sdd: MBR Magic : aa55 Partition : 4980480 sectors at 256 (type fd) Partition : 4194304 sectors at 4980736 (type fd) Partition : 3897586881 sectors at 9437184 (type fd) # mdadm --examine /dev/sdd3 mdadm: No md superblock detected on /dev/sdd3.
As a result I am unable to mount the partition. The data is there and it is recognized by tools like
I have also tried using
extundelete, but it fails without a proper ext superblock.
# extundelete --superblock /dev/sdd3 extundelete: failed to read-only open device "/dev/sdd3": Error code 2133571347
How to recover files and directories from a corrupted RAID1 partition?
Is there any way to recreate the
md superblock, without loosing the existing data?
Would it be possible to ignore the md parts, to treat the partition as a corrupted
ext4 partition and recover it that way?