Ubuntu – How to mount/recover data on a disk that was part of a mdadm raid 1 on another machine

data-recoverymountsoftware-raidUbuntu

Some background

  • The disk itself was "worked on" by a friend and is said to be still intact, undamaged and still mountable/recoverable
  • The disk was part of a software raid 1 on Ubuntu 12.04
  • The other disk in the original raid 1 was formatted and used for another purpose, leaving the current disk (the one in question) still technically part of a raid that no longer exists

What I have tried already

  • Basic mounting

    • I added an entry to fstab, marked the disk as ext3/ext4 and tried to mount.

    • Upon mounting the following error appears

      wrong fs type, bad option, bad superblock on

    • And in dmesg

      EXT4-fs (sdc1): VFS: Can't find ext4 filesystem

  • I have tried to find the file system type of the disk and have come up with

    $sudo file -s /dev/sdc
    /dev/sdc: x86 boot sector; partition 1: ID=0x83, starthead 254, startsector 63, 1953520002 sectors, code offset 0xb8

Where I need some help / My Questions

  • Is there a way to convert the disk to ext4 without damaging the data?
  • Is there a simple way to mount the Linux 83 file type disk and recover the data?
  • I have another disk currently free in case it is a possibility to somehow rebuild the raid
  • My main goal is to recover the data from the disk. I am open to all options.

Update

Some commands' output

  • fdisk -l /dev/sdc

    $fdisk -l /dev/sdc

    Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
    255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 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: 0x0005ed9c

    Device Boot Start End Blocks Id System
    /dev/sdc1 63 1953520064 976760001 83 Linux

  • file -s /dev/sdc1

    $file -s /dev/sdc1
    /dev/sdc1: data

  • hexdump -C -n 32256 /dev/sdc (Not sure if this could help or not)

    $hexdump -C -n 32256 /dev/sdc`
00000000  fa b8 00 10 8e d0 bc 00  b0 b8 00 00 8e d8 8e c0  |................|
00000010  fb be 00 7c bf 00 06 b9  00 02 f3 a4 ea 21 06 00  |...|.........!..|
00000020  00 be be 07 38 04 75 0b  83 c6 10 81 fe fe 07 75  |....8.u........u|
00000030  f3 eb 16 b4 02 b0 01 bb  00 7c b2 80 8a 74 01 8b  |.........|...t..|
00000040  4c 02 cd 13 ea 00 7c 00  00 eb fe 00 00 00 00 00  |L.....|.........|
00000050  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
000001b0  00 00 00 00 00 00 00 00  9c ed 05 00 00 00 00 fe  |................|
000001c0  ff ff 83 fe ff ff 3f 00  00 00 82 59 70 74 00 00  |......?....Ypt..|
000001d0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
000001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|
00000200  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00007e00

Best Answer

This is working excellently in Ubuntu 14.04: 

sudo -i
mdadm --assemble --scan

You will get:

mdadm: /dev/md/1 has been started with 1 drive (out of 2)

Then mount and see your files:

cd /mnt && mkdir to-restore-md1 && mount /dev/md1 to-restore-md1
ls -la to-restore-md1
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