Yesterday, we reported that Facebook's hardware program has saved the company "more than a $1 billion in the last three years," according to CEO Mark Zuckerberg.
Today, we found out that along with its innovative server designs, it's worked out an extremely cost-efficient solution for keeping data that's rarely accessed, known as "cold storage."
Rather than using hard drives, flash storage, or old-fashioned tape drives, Facebook's design relies on a whopping 10,000 Blu-rays to store one petabyte — that's a million gigabytes — of things like duplicates of user photos and videos.
James Niccolai at IDG News Service reports that the system "reduces costs by 50% and energy use by 80%," which is a huge deal when you're talking about the scale that companies like Facebook, Google and Amazon are operating at. Yesterday, Zuckerberg also noted that its custom technology has already saved the equivalent energy of that used to power 40 million homes and reduced carbon emissions by an amount "equivalent to taking 50,000 cars off the road for a year."
Blu-rays work well for this kind of storage for a few reasons:
- Discs are cheap. They cost far less than a hard drive for the amount of storage you get for your dollar, which is why Facebook is looking to eventually expand its use of Blu-rays to 5 petabytes of storage.
- Blu-ray discs might be able to hold more in the future. Manufacturers still haven't hit the theoretical limits of how much can fit on a single disc, so the price it would pay to expand this storage is likely to fall further in the future as well.
Of course, Blu-ray does have a few disadvantages as well. Chief among them is access speed. That's why Facebook plans to eventually move to low-power flash storage, like that in your phone or tablet.
Facebook says it's going to put its Blu-ray system into production tests later this year, but it's likely going to be a temporary solution until flash storage reaches the right balance of power usage, storage density, and cost that Facebook needs to deploy at scale.
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