One of the interesting discussions I had during HP Discover was an HP 3PAR StoreServ 20800 architecture discussion with folks on the show floor. At first glance, you’ll notice a large enclosure in the 20800’s cabinet in the photo to the right from the event and also prominently shown in the marketing photos. I was immediately curious what was inside of this enclosure.
Turns out, these 16U enclosures are actually the 8 controllers for a 20800 array. The enclosure is a lot like a blade enclosure with modular controllers that can be added from the back of the enclosure. On the front, there is a bank of fans and batteries for the individual controller nodes. The 8 controllers are wired together through a mid-plane, very simliar to a blade enclosure, and this shared mid-plane eliminates the needs for many wires that would normally wire together these nodes in the “mesh active” architecture. The first thought is that field upgrades should be much simpler due to decreasing the amount of complex wiring required.
In addition to the controller enclosure, another major change in architecture is SAS backend for the 20800 series arrays compared to the 10800 series arrays they replace. The drive enclosures are all connected back to the controllers with SAS cables and the folks I spoke with said that in the field, it should not be necessary to have more than a couple chained SAS connections from the controller to the drive enclosures even in a fully populated array because the controllers have so many available SAS ports. This again keeps things simple for field upgrades.
Not only did the drive enclosures switch to SAS connections, but HP is also introducing a fiber SAS connectivity between the controllers and the drive enclosures to allow the rack of drive enclosures to be locate further away from the controllers themselves in crowded data centers. These connections can extend up to 100 meters according to the people I spoke with. The gallery below shows a little more detail of these changes.