Disk

Backblaze reports disk drive failure rates for Q3

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Backblaze’s monthly disk drive stats tell a different story this month with odd failure rate rises

Cloud storage supplier Backblaze puts out quarterly annual failure rate (AFR) statistics for its hundreds of thousands of disk drives, with AFR percentages for each of its many different disk drive product models. Generally, newer disk drives have lower AFRs and the overall trend is down, but not so in the July-September quarter.

Here’s the quarter’s table of AFRs by disk drive model;

The failure rate increased from last quarter’s 1.36 percent to this quarter’s 1.55 percent, which compares to the full 2024 year failure rate of 1.57 percent. It was driven up by three drives:

  • 16 TB Toshiba – model number G08ACA16TEY – 16.95 percent
  • 10 TB Seagate – ST10000NM0086 – 7.97 percent
  • 14 TB Seagate – ST14000NM0138 – 6.86 percent

The Tosh drive is less than four years old (44.61 months), and Backblaze has 5,145 of these drives in total. There is a sharp AFR uplift this quarter, as a chart shows;

But it turns out to be an artefact of the way the Backblazers define a failure, which includes pulling out drives for firmware updates. This is what happened with these Tosh drives. So much ado about nothing.

The 10 TB Seagate model’s high AFR was attributed to it being “well over seven years old (92.35 months). And, since it only has 1,018 drive models in operation, single failures hold a lot of weight compared with the average drive count per model—which comes in at 10,952 if you use the mean of this quarterly data and 6,177 if you use the median.”

The 14 TB Seagate model “is nearing five years in age (56.57 months) and, again, has a lower drive count at 1,286.” But it has historically had quite a high AFR;

It is a poor drive AFR-wise.

The three high AFR drives have high failure rates for different reasons and there is no unifying factor. Move on. Nothing to see here.

Four drives had a zero percent AFR:

  • Seagate 4 TB – HMS5C4040BLE640
  • Seagate 8 TB – ST8000NM000A
  • Toshiba 16 TB – MG09ACA16TE
  • Toshiba 24 TB – MG11ACA24TE

Backblaze notes the 8 TB Seagate ST8000NM000A last had a failure in Q3 2024, and it was a single failure for the whole quarter.

Get access to the full Backblaze AFR blog here.

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