Every quarter, Backblaze releases a report that accounts for the thousands of hard drives it uses in its proprietary Storage Pod enclosures, and the failure rates it calculates for those drives. Each Storage Pod contains as many as 60 3.5" drives in four units of rack space. The company's report for this quarter came out today, and it's full of juicy data.
The report for the first quarter of 2016 stands out in one big way from previous reports. In this document's past installments, Seagate has been hit hard by a set of particularly failure-prone drives—namely the 3TB ST3000DM001. Numbers for those drives have been removed from the current report since Backblaze has fewer than 45 of them in service. Seagate's reliability figures without the ST3000DM001 looks pretty respectable:
Backblaze's numbers show that HGST continues to be the reliability champion of all of its disks in its pool. All of the service's HGST drives had failure rates of less than 2%. That result continues HGST's "most reliable" streak, a run that's extended for as long as Backblaze has been releasing data. Western Digital drives knocked Seagate's off the podium for highest failure rate overall. All told, though, drives from every vendor had a lower failure rate this quarter than in the recent past. Each company other than HGST has one disk model that stands out as particularly failure-prone.
There are a few caveats to this study, though, and it's not a perfect parallel to home use. As we mentioned before, the drives are kept in extremely high-density servers. They are also run with a very low power-cycle count, in temperature controlled environments. Still, this is one of the best resources available with real-world data on hard drive reliability.
If you think having 60 3.5" SATA disks stuffed in a 4U chassis is a great idea for your home, you're in luck. Backblaze publishes an open-source list of components, blueprints, and STEP guides for its Storage Pods so you can build your own. If you're more into the data than the disks, take a look at the full failure rate stats.