I've done a clean install with a spare 1gb drive that was used in my DS508 few years ago. It's recognized in DSM but not used yet.
I've added another 1gb spare drive in my DS508, created a new volume with SHR raid and uploaded 2 files on it.
Then I've moved that disk into the N54L and DSM has automaticaly recognized the new disk, created a Raid Group 1 and recovered Volume 2 detected with SHR raid. The first spare drive is still marked as unused.
However the Storage Manager Overview shows an Attention message as it fails to access to system partition, asking to repaire it. When I click on the Repair linlk and I confirm, nothing happens.