• HP microserver gen8

  • 1x1TB - standalone, 2x4TB Raid

  • 1x16GB iLO SDCARD with Debian + OpenMediaVault


  • SDCARD failure

  • restarted server and installed Ubuntu on 1TB drive


  • ZFS not accessible anymore

    root@fremen:~# sudo lsblk -o NAME,FSTYPE,SIZE,MOUNTPOINT,LABEL
    NAME   FSTYPE       SIZE MOUNTPOINT                    LABEL     
    sda    zfs_member 931,5G                               
    └─sda1 ext4       931,5G /                             
    sdb    zfs_member   3,7T                               
    └─sdb1 zfs_member   3,7T                              
    sdc    zfs_member   3,7T                               
    └─sdc1 zfs_member   3,7T                               
    sdd                 5,7G
    root@fremen:~# zpool import -D -f 
    no pools available to import
    root@fremen:~# file -s /dev/sd?1
    /dev/sda1: Linux rev 1.0 ext4 filesystem data, UUID=9c46f52c-b529-4c39-a23b-819726f79146 (needs journal recovery) (extents) (64bit) (large files) (huge files)
    /dev/sdb1: data
    /dev/sdc1: data
  • Disks seem to be still on the ZFS pool but no data is accessible.

What to do in this situation? It is a friend's setup and I can connect remotely to the machine. I do not want to create a new pool as it will destroy data on ZFS volumes. As I cannot find pools on disks zdb cannot be used.

  • Don't use -D with zpool import. – Michael Hampton Mar 1 at 18:45
  • @MichaelHampton: Even without '-D' there is no available pool. – Daniel Voina Mar 1 at 19:32
  • That's really odd. Was there actually a zpool there? Did someone erase it? You might need to restore from backup. – Michael Hampton Mar 1 at 19:57
  • Indeed, it is odd. The only idea that I have right now is that the pool info was written on the iLO sdcard and now cannot be accessed. I'm wondering how to dig deeper for data. Unfortunately I couldn't find any tool able to do low level disk inspection (a la testdisk) so that I can recover some of his files. – Daniel Voina Mar 1 at 20:03
  • Please post the output of file -s /dev/sd?1 – Michael Hampton Mar 1 at 20:05

Michael Hampton comments were the solution for this.

It turns out that OMV in fact didn't use ZFS at all but just marked the drives as ZFS members.

I have dd-ed one of the drives and on the image I ran testdisk. It turned out that there was a 0x0700 partition on the disk. Wrote a new partition table with testdisk and mounted it in loop. It turned out to be an ext4 partition with corrupted journal. After fixing the errors I was able to salvage all the data. Hence I did the same on the physical disks, got the data back.

  • Thanks for sharing the method of using dd first and working with the image. That's really something I'll remember forever. – Louis Mar 21 at 5:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.