I am on the West Coast of the US this week visiting with NetApp in Sunnyvale again. On this trip I had the opportunity to visit a couple of NetApp’s internal data centers (B11 and the impressive B2 sites) with Cesar Orosco, NetApp on NetApp IT Architect. Cesar is charged with using NetApp technology in innovative ways to maximize value whilst containing costs and reducing NetApp’s environmental footprint.
Cesar took me around and showed me the two sites, one retrofitted to be low energy and the other designed from the outset yo use as little power as possible. Electricity in Silicon Valley costs around 12c – 14c per KW hour, cheap by European standards but still expensive. Much too expensive to waste.
The retrofitted B11 data center is quite impressive for a low density site with a number of key features that are worthy of note:
There is no raised floor area and all equipment rests on the concrete floor slab. In an earthquake zone this is actually quite a big deal from a physical stability perspective. I have been saying for years that raised floors are unnecessary and actually an impediment to effective IT operations. NetApp have been able to dispense with the raised floor by adopting two key principles:
- Cold air is inserted from the ceiling (so that it falls naturally towards the bottom, front part of the racks whilst hot air is extracted from the ceiling where it naturally rises from the rear of the racks.
- All power and network delivery is made via a set of cable routing trays suspended above the racks.
To support the data center’s efficient use of airflow, plastic curtains are used to separate the front of the racks from the back. (These are exactly the same curtains that we used at BT some years ago and I blogged about on The Hot Aisle)
Cesar has also deployed some clever and cheap, roll up plastic blanking plates that close off any open slots in the racks and prevent short circuiting of the airflow. These are quick and cheap to implement and make an enormous difference to data center efficiency.
The most interesting part of the trip was seeing another big BT Data Center innovation, fresh air cooling. NetApp use large building scale filters to remove dust and contamination. The first is mounted into the fresh air inlets in the building and the second filter is an integral part of the air handling units. Cesar tells me that these units are able to run on fresh air only for 68% of the year. This makes a dramatic saving on chiller running costs and with the hot aisle containment curtains contributes to a year round PUE of about 1.35.
Power to the site is from a co-generation set with absorption chillers, these are used to further reduce the costs of running refrigeration.
The B11 site is small, 720KW total power but the work Cesar and his team have done to retrofit efficiency has led directly to an annual cash saving of nearly $300k for this area alone.
I have some great photographs of the site that I will publish in a future blog as well as some observations about the much larger B2 site that was designed from the outset for efficient operation.