Good post by the Maximum Midrange Team (thank you) and thank you to Max Hogan for the hint
Quick explanation of Storwize systems:
A Storwize system, whether it is the V3700, V5000, V7000 or the V7000FS, is made up of one or more enclosures.
Each system requires a control enclosure, which can then be built out with expansion enclosuresto grow with your storage needs.
Each enclosure holds a maximum of either 12 or 24 drives depending on the physical size of the drive.
– Enclosures designed for the larger 3.5-inch drives hold a maximum of 12 units.
– Enclosures designed for the 2.5-inch small form factor drives max out at 24 units.
Read on here