How to easily migrate a Synology EXT4 volume to Btrfs without data loss

Today I switched from a Synology DS215play to a DS918+. Perfect time to change the file system – the DS215play didn’t support Btrfs. The migration also works with only one device. So I wrote down both ways.

Steps if you haven’t changed your DiskStation

  • Backup your data! If you switch to a device with new drives like me, you still have a copy of your data, but if you migrate without new drives, you don’t have a copy! In germany we say: No backup – no pity.
  • Shut down the DS, remove drive 2.
  • Format drive 2 with your computer.
  • Insert drive 2.
  • Turn the DS back on and DO NOT repair the fault volume.
  • Create a new volume (SHA and Btrfs) in the Storage Manager on drive 2.
  • For each shared folder, change the location to the new volume. You can only do this for one shared folder at a time and the move may need several hours depending on the size of your shared folders.
  • When you have moved all the shared folders, shut down your DS and remove drive 1.
  • Format drive 1 with your computer.
  • Turn on your DS and go to the Package Center. Repair all apps.
  • Expand your new volume to drive 1 and wait until RAID Resync is complete. You’re done.

Steps if you are switching to a new DiskStation with new drives (my situation)

  • Turn off your old DS, remove drive 2.
  • In the new DS, place the new drives in slot 1 and 2. Place the (old) drive 2 in slot 3.
  • Turn on the new DS. Open your browser and navigate to the new DiskStation. In my case, the DS got a new IP address. I looked them up in my router DHCP table.
  • Follow the Migration Wizard and wait until the DS restarts.
  • Create a new volume (SHA and Btrfs) in the Storage Manager on drive 1 and 2. It is now recommended to change the RAID Resync speed to Fast and wait until RAID synchronization is complete.
  • Now for each shared folder, change the location to the new volume. You can only do this for one shared folder at a time and may need several hours depending on the size of your shared folders.
  • When you have moved all shared folders, shut down your DS and remove drive 3.
  • Turn on your DS and go to the Package Center. Repair all apps. You’re Done.