Backblaze: Failure rate of 8TB HDDs equal to 2TB models after migration

Cloud service provider Backblaze is pleased after the migration of thousands of 2TB HDDs from HGST and WDC to a lower number of 8TB copies from Seagate. The annualized failure rate of the Seagate drives is consistent with the high-performing HGST drives.

Last quarter, Backblaze shut down 3,405 2TB HGST HDDs and 138 2TB WD drives and migrated data to 2,400 new 8TB Seagate HDDs. “We’ve lost more than 1,100 hard drives but have added 12 petabytes of storage,” the company said. The move is part of a migration process that started a quarter earlier and saw the addition of 32 petabytes by deploying a total of 5120 new 8TB drives from Seagate.

Taking into account the costs of the HDDs, migration, consumption and other factors, such a switch is already justifiable, but according to the company, the failure was an uncertain factor, because the HGST drives had performed well. “Outages are to be expected, but our costs will go up if the new drives fail two to three times as much as the 2TB variants.”

This appeared to not be the case. The annualized failure rate comes out at 1.60 percent, just like that for the HGST HDDs. Given that the average age of those drives was 66 months, it was expected that the dropout rate would increase, Backblaze said.

Backblaze has become famous for publishing hard drive reliability statistics. In the past, this showed, among other things, that certain 3TB drives from Seagate often failed. It should be noted in the results that these are regular HDDs that are subject to a higher load than consumer use. For this kind of workload, manufacturers have more expensive enterprise models in their range, which Backblaze does not use. Also, when interpreting the list of failure rates, low sample rates in some models must be taken into account.