I bought a QNAP TS-451+ NAS a number of years ago. At the time, you could only set up what are now called "static volumes"; these are volumes that are composed of a number of disks in some RAID configuration. After a firmware update, QNAP introduced "storage pools", which act as a layer in between the RAIDed disks and the volumes on top of them. Storage pools can do snapshots and some other fancy things, but the important thing here is that QNAP was pushing storage pools now, and I had a static volume.
I wanted to migrate from my old static volume to a new storage pool. I couldn't really find any examples of anyone who had performed such a migration successfully; most of the advice on the Internet was basically, "back up your stuff and reformat". Given the fact that my volume was almost full and that QNAP does not support an in-place migration, I figured that if I added on some extra storage in the form of an expansion unit, I could probably pull it off with minimal hassle.
(The official QNAP docs generally agree with this.)
tl;dr It was pretty easy to do, just a bit time-consuming. I'll also note that this was a lossless process (other than my NFS permissions); I didn't have to reinstall anything or restore any backups.
Here's the general workflow:
- Attach the expansion unit.
- Add the new disks to the expansion unit.
- Create a new storage pool on the expansion unit.
- Transfer each folder in the original volume to a new folder on the expansion unit.
- Write down the NFS settings for the original volume's folders.
- Delete the original volume.
- Create a new storage pool with the original disks.
- Create a new system volume on the main storage pool.
- Create new volumes as desired on the main storage pool.
- Transfer each folder from the expansion volume to the main volume.
- Re-apply the NFS settings on the folders on the main storage pool's volumes.
- Detach the expansion unit.