The DS215+ is the smallest member in Synology's product line for small- and medium-sized business environments, and it doesn't share the same hardware with the DS415+ we had the chance to evaluate a while ago. We should also mention that the DS215+ can be connected to a Synology DX513/DX213 expansion unit through its eSATA port; however, there is a catch: connect an expansion unit to the DS215+ and it won't increase the size of its internal volume to, instead, allow for independent volumes with the additional storage space inside the expansion unit. This doesn't pose a serious drawback, but we had to point it out for those particular situations where there is the need for a single volume only.
