BackBlaze reports unexpectedly high failure rate for one of Seagate’s 12TB drives

BackBlaze has reported “a higher-than-typical failure rate among some of our 12TB Seagate drives” at its cloud storage facility.

In a recent hard drive stats report, Yev Pusin, BackBlaze’s director of marketing, notes Seagate’s ST12000NM0007 12TB drive has a 3.32 per cent annualised failure rate (AFR).

This is worse than the previous least-reliable drive, a 4TB Seagate model with two per cent AFR. Backblaze has two HGST 12TB drive models and their AFRs are 0.4 per cent and 0.56 per cent, as the table below shows. 

A chart of the drive model AFRs indicates how Seagate’s 12TB drive stands out.

In 2017 and 2018, the 12TB Seagate drive’s AFR was 2.01 per cent and 1.39 per cent.

“It’s worth noting that situations like this are not uncommon in our industry and often go unnoticed by the end-users of the services,” Pusin wrote, “as most cloud providers do not inform customers or the public when they experience issues like what we’re describing.”

Testing new drive platforms

BackBlaze is working with Seagate to understand what’s going on. This work involves “things like testing new drive platforms in real workload environments, providing telemetry tools to predict failures, performing ongoing custom adjustments, and employing firmware development and replacement units (RMAs). … we’re also working together on a migration effort to replace these particular drives in our data centres.”

As a fix, the company is migrating to a different Seagate 12TB drive model, the ST12000MN0008, and is also looking at 14TB and 16TB drives.

Pusin said: “In the near term, we expect to see moderately increased failure rates for this specific subset of 12TB drives, but as we complete the drive migration, we project our fleet’s failure rates will restore to historical norms.”

Backblaze customers should be unconcerned because the company’s processes mask drive failures and recovery.