Backblaze stats on 27,000 hard drives show which ones keep on ticking

chart showing drive failure rates

When your business value proposition is delivering inexpensive, reliable cloud backup for thousands of customers, you're going to learn a thing or two about drive reliability. The Backblaze team has been sharing that HDD savvy (gleaned from several years' experience and more than 75 petabytes of storage) in a series of blog posts over the past couple of months, and we've been fascinated to note their discoveries. Now Brian Beach at Backblaze has addressed the eternal question: What hard drive should I buy?

BB's StoragePods are packed with consumer-grade hard drives just like the ones you'd buy at Costco or Best Buy, so it's reasonable to use Backblaze's failure stats as a proxy for how these drives might perform on your very own desk with your very own Mac. Granted, drives in a StoragePod are in more continuous use and subject to more vibration than a home-use drive, so your mileage may vary.

Of the 27,000-plus drives running in Backblaze's server racks, the vast majority (almost 13,000 each) are Seagate or Hitachi models. There are only a couple of drives that Backblaze won't buy or try -- WD's Green 3TB drives and Seagate LP (low power) 2TB models -- because the BB StoragePod environment doesn't agree with them, possibly due to vibration sensitivity on spin-down/spin-up. Other than that, the company buys drives on a commodity basis, going with the best GB/$ ratio available at a given point in time.

Best of the BB batch? Hitachi/HGST's Deskstar 2 TB, 3 TB and 4 TB models. Beach says, "If the price were right, we would be buying nothing but Hitachi drives. They have been rock solid, and have had a remarkably low failure rate." At the moment, due to price fluctuations, the drives of choice are a Seagate HDD.15 4 TB unit and the Western Digital 3 TB Red.

As Beach notes, however, Hitachi's storage unit (originally purchased from IBM in 2002) has been bought (and split) in the past two years, with the 3.5-inch business going to Toshiba and the 2.5-inch product line going to WD. Although HGST is still marketing and making the Deskstar line, it's likely that technology will settle under the Toshiba brand in the future.