Thanks to a report from Wired, we now know that the mini-datacenter (code named Sub-Zero) that Facebook is building as an add-on to their existing Oregon datacenter campus, will be dedicated to datacenter backup. According to the report, Facebook will use a new type of low-power deep storage device that doesn’t currently exist.
Facebook is apparently setting their engineering staff on the task of designing what sounds like an on-demand backup system, that, when quiescent, is powered down and the datacenter housing it will be optimized to support this type of operation. Facebook currently uses a disk-to-disk backup process, with one live copy and one archival copy of the data created. This is a fairly common backup process, and Facebook skips what is often the final step. There is no move to tape storage as the ultimate archival target.
It’s not often that any company, much less one with the data needs of Facebook, has the opportunity to build a backup solution from scratch, especially with a mandate to develop new technologies and methodologies. The very nature of Facebook and its data storage and backup requirements makes this an amazing opportunity for an interesting, and possibly revolutionary approach to backing up huge, rapidly changing, data stores
The report makes it sound like the primary goal of the backup solution is to drop power consumption from the 4.5 kW/rack that the running servers take to around 1.5 kW/rack for the dedicated backup racks. Simply reducing the amount of power that each rack consumes will have additional benefits in efficient energy utilization, as reduced power consumption also translates into reduced cooling requirements, which circles back around to reducing the overall power consumption of the facility.
Facebook is giving its engineers a six to nine month window to develop the backup technology for this dedicated datacenter. It should be a very interesting announcement when the project comes to fruition.