Wait, so the expansion bay wouldn't allow me to address all discs as one big storage array?
I thought I'd read that somewhere, but the Synology site
suggests otherwise:
The RAID volume on the Synology DiskStation can be expanded directly without having to reformat the existing hard drives, ensuring the Synology DiskStation continues its service during the capacity expansion.
So I'm probably wrong. Still, it might not hurt checking before making the final purchase.
I'm also wondering what happens if eg. you're running 10 disks in a 1512+ and DX513 expansion bay and the power drops by accident on the DX513. In that case, more than one disk is "lost", which is more than RAID5 can handle.
Would that mean the entire array would be lost and all the data gone? In that case I would surely also invest in a big fat UPS, just to make sure!