NAS326 problem - part 2 - help is needed - Volume is down

Janikovo
Janikovo Posts: 24  Freshman Member
edited June 2020 in Personal Cloud Storage
Hello all,
and especially @Mijzelf

You probably know my problem with one faulty disk on NAS326 (linear, jbod).
Look here: https://homeforum.zyxel.com/discussion/3827/nas326-problem/p1

Problem is how to "assemble" NAS volume (or array back) without losing data.

So, I managed with ddrescue copied 99.999% of that faulty disk to the news HDD same size.

Installed the new disk to NAS, but the situation is as follows:



















What should I do now ?
Please an advice
and Thanks.

#NAS_June_2020

All Replies

  • Mijzelf
    Mijzelf Posts: 1,975  Guru Member
    The array is assembled, but it fails to mount. So try running fsck:

    e2fsck /dev/md2
  • Janikovo
    Janikovo Posts: 24  Freshman Member
    @Mijzelf

    ~ # e2fsck /dev/md2
    e2fsck 1.42.12 (29-Aug-2014)
    /dev/md2 is in use.
    e2fsck: Cannot continue, aborting.

    Thats all.
  • Janikovo
    Janikovo Posts: 24  Freshman Member
    edited June 2020
    OK,

    i tried add -n to e2fsck

    and it show this:

    ~ # e2fsck -n /dev/md2
    e2fsck 1.42.12 (29-Aug-2014)
    Warning!  /dev/md2 is in use.
    ext2fs_open2: Bad magic number in super-block
    e2fsck: Superblock invalid, trying backup blocks...
    e2fsck: Bad magic number in super-block while trying to open /dev/md2

    The superblock could not be read or does not describe a valid ext2/ext3/ext4
    filesystem.  If the device is valid and it really contains an ext2/ext3/ext4
    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>
     or
        e2fsck -b 32768 <device>

    btw:
    mdadm --stop /dev/md2:

    ~ # mdadm --stop /dev/md2
    mdadm: Cannot get exclusive access to /dev/md2:Perhaps a running process, mounted filesystem or active volume group?

    So, I cant stop md2

    How could I assemble volume (array) without losing data ?


  • Mijzelf
    Mijzelf Posts: 1,975  Guru Member
    So, I cant stop md2

    You can't stop md2, because it's busy. md2 is not mounted, so there must be something else. I should have looked further, apart from md2 there is also a dm-1 in /proc/partitions, which is slightly smaller than md2. So inside your raid array there is a 'logical volume', and that logical volume is the one containing the file system.

    So try

    e2fsck /dev/dm-1

    I am not sure if that dm-1 devicenode is inside /dev/. If /dev/dm-1 cannot be found, try

    find /dev/ grep dm

    to find the path to the devicenode.