recovery_(mergerfs,snapraid).md

Recovery w/ MergerFS & SnapRaid

This assumes a setup similar to what is described here.

Full drive recovery

Initial state

• 4 Pooled Drives
  • /mnt/data0
  • /mnt/data1
  • /mnt/data2
  • /mnt/data3
• Pool mountpoint: /mnt/pool
• Parity drive: /mnt/parity0
• Failed drive: /mnt/data1
• New drive: /mnt/data4

Restore Procedure

1. Read the SnapRaid manual
2. Modify /etc/snapraid.conf to include the new data drive:
   disk disk1 /mnt/data1
   becomes
   disk disk1 /mnt/data4
3. Fix the drive (will take a long time):
   $ snapraid -d disk1 -l /tmp/snapraid-disk1-fix.log fix
4. Check that the data is OK (will take a long time, skippable):
   $ snapraid -d disk1 -a check
5. Resync with new drive:
   $ snapraid sync
6. Remove old drive from mergerfs pool:
   $ sudo xattr -w user.mergerfs.srcmounts -/mnt/data1 /mnt/pool/.mergerfs
7. Add new drive to mergerfs pool:
   $ sudo xattr -w user.mergerfs.srcmounts +/mnt/data4 /mnt/pool/.mergerfs