NAS -  Into which NAS models can I put my drives without formatting?

If you bought a new NAS and you what to just plug in the old hard drives into the new NAS, you have to be very careful. The NAS series uses a software RAID to manage the files on it. We recommend to plug in hard drives only to the exact same model, for example, NAS542 > NAS542 

NAS 542 > NAS326 will not work!

Furthermore, the NAS may see the RAID as degraded, so you need to repair it. All shares that have been available on the old NAS will be either disabled or simply not available.

We always recommend creating a backup of the files on an external hard drive.