Sunday, 31 July 2022

Recovering from a Failure / SMART ERROR RAID 1 situation

The situation

You have an DL380 or similar. Your first disk has failed.  Your second disk is in SMART ERROR.

What next?

The hardware

You will need:
  • a USB adapter for mounting your disk on Windows
  • the failed disks

The software

You will need
  • Windows 10/11
  • Windows Subsystem for Linux installed

The process

  1. Attach the disk to USB via the adapter
    • If the disk is Windows-compatible, you can use freeware disk recovery tools to go from here.  Do not follow the following steps.
    • If the disk is Linux-compatible, proceed to the next step
  2. Start Disk Manager to ensure that you are able to see the disk partition
  3. Start an elevated PowerShell prompt
  4. Type:
    • wmic diskdrive list brief
  5. Note the drive that you want to mount
  6. Type (e.g.)
    •  wsl --mount \\.\PHYSICALDRIVE2
  7. If you receive an error:
    • The disk \\.\PHYSICALDRIVE2 was attached from WSL2, but failed to mount (error code: -22). For more details, run 'dmesg' inside WSL2.
    • ... then you likely have a different file system to EXT4.
  8. Enter WSL with:
    • wsl --system
  9. Look at the dmesg output by typing:
    • dmesg
  10. Look for the following (or similar):
    • [224440.126973] EXT4-fs (sde): VFS: Can't find ext4 filesystem
    • [224440.127932] ERROR: Mount:2528: mount(/dev/sde, /share/PHYSICALDRIVE2, ext4, 0x0, ) failed
  11. Note the disk, in this case "sde"
  12. Make a data directories for each partition:
    • mkdir /data1
    • mkdir /data2
    • mkdir /data3
    • ...
  13. Mount each partition - the command will fail when there are no more partitions to mount:
    • mount -t xfs /dev/sde1 /data1
    • mount -t xfs /dev/sde2 /data2
    • mount -t xfs /dev/sde3 /data3
    • ...
  14. Now copy the data off to your home directory using the rsync command (cp has issues with large files)
    • Install rsync with:
      • yum install rsync
    • Have progress bars on your file copy with (e.g.):
      • rsync --progress /data1/110/disk.0 .
  15. When you are finished, remember to unmount the partitions:
    1. umount /data1
    2. umount /data2
    3. umount /data3
    4. ...
  16. You can now unplug the drive.