Их там три штуки.
Each IBM Storwize V7000 system has one control enclosure that contains two node
canisters, disk drives, and two power supplies. There are two models of the control enclosure
with one model providing 12 3.5-inch disk slots and the other providing 24 2.5-inch disk slots.
Within a control enclosure, each power supply unit (PSU) contains a battery. The battery is
designed to enable the IBM Storwize V7000 system to perform a dump of the cache to
internal disks in the event of both power inputs failing.
Хм… а где третья?