Hard-disk drives becoming more reliable, Backblaze failure figures suggest

Cloud storage company hard-drive failure figures for 2018 suggest HDDs have improved in reliability

Cloud backup company Backblaze has released its hard-disc drive failure rates for 2018, with the figures indicating that mechanical hard-disk drives are improving in reliability.

The company runs more than 100,000 hard-disk drives on its server farm, from three main vendors - Seagate, Western Digital and Toshiba - and claims that the overall annualised failure rate across its estate stands at just 1.25 per cent, despite the daily pounding that the storage hardware takes.

Only one make and model of HDD registered zero failures during 2018, a five terabyte Toshiba model (MD04ABA500V), although that was based on a drive count of just 45. The company also added 1,200 HGST 12TB drives to its infrastructure and has had only one failure in the month they've been running. HGST is owned by Western Digital.

In addition to the most reliable model, Toshiba also came in with the least reliable: the helium-filled 14TB (MG07ACA14TA) model, which boast perpendicular magnetic recording technology. Out of 1,205 drives and an estimated 108,536 ‘drive days', it suffered nine failures. Backblaze pegged its annualised failure rate at 3.03 per cent.

For 2018, the Annualized Failure Rate (AFR) stated is usually pretty solid. The exception is when a given drive model has a small number of drives (fewer than 500) and/or a small number of drive days (fewer than 50,000). In these cases, the APR can be too wobbly to be used reliably for buying or retirement decisions," the company explained.

It continued: "In 2018 the big trend was hard drive migration: replacing lower density two, three, and four terabyte drives, with eight, 10, 12 and, in the fourth quarter, 14TB drives.

"In 2018 we migrated 13,720 hard drives and we added another 13,389 hard drives as we increased our total storage from about 500 petabytes to over 750 petabytes. So in 2018, our data centre techs migrated or added 75 drives a day on average, every day of the year."

It is the fifth year that the company has published its hard-disk drive reliability figures, during which time the market has consolidated as SSDs make in-roads into both the consumer and enterprise markets.

Back when the first report was published, Seagate drives were the least reliable by far, with its 1.5TB models run by Backblaze running at close to a 14 per cent failure rate. Hitachi - whose HDD business has been absorbed by Western Digital - provided the most reliable.

The company also provided some comparison figures from 2016 to the latest 2018 figures, indicating that the annualised failure rate of hard-disk drives had fallen from 1.95 per cent in 2016.

And, responding to questions, Backblaze's director of product marketing Andy Klein suggested that the company would continue to rely on conventional HDDs well into the future for storage, rather than migrating to SSDs.

This, he added, would be despite the fall in price of the faster storage technology, due to the much lower cost per terabyte of HDDs - especially as capacities have continued to radically increase.