The Long Decline of the Hard Disk Drive

Many have long-predicted the end of the hard disk drive. But a recent report from Backblaze has thrown some doubt at this. Could we be seeing a slow but delayed demise?

Hard disk drives (HDDs) are mechanical, and while they’re much more susceptible to physical damage, the data recovery process is much simpler. But magnetic platters are also capable of holding cast amounts of data, and this is one of the reasons why the hard drive hasn’t been completely replaced by the solid-state drive (SSD) just yet. One of the main drawbacks of hard disk drives in their limited lifespan, particularly if they see a lot of use. But how much of a problem is this with modern hard drives?

Blackblaze’s recent report detailing hard drive stats for the first quarter of 2020 is incredibly interesting, as it shows that modern hard drives are actually quite resilient. Spread across four data centres, Backblaze’s cloud storage ecosystem has 132,339 spinning hard drives. These hard drives are sourced from a range of manufacturers, and vary in capacity from 4TB to 16TB. With so many drives deployed across their four data centres, Backblaze has a unique insight on hard drive durability. The report notes that the Annualised Failure Rate (AFR) for Q1 was 1.07%, the lowest for any quarter since Backblaze started keeping track in 2013. This marks a significant improvement on Q1 in 2019, which saw an AFR of 1.56%. In Q1 of 2020, four hard drive models from three manufacturers had no failures. Backblaze calculates the AFR using the equation drive failures/ (drives days/366) * 100. Drive days represents the number of days that all of the drives being observed were operational, and 366 is used because 2020 is a leap year.

Backblaze made several predictions based on the stats in Q1 2019. Firstly, they predicted that the number of 4TB would decrease by more than half, from 35,000 to 15,000; in reality, adding drives took priority, and by Q1 2020 there were only marginally fewer 4TB drives. Secondly, they predicted they would have at least twenty 20TB hard drives provided for testing; they received none. Thirdly, that they would have received at least one HAMR drive from Seagate, and/or one MAMR drive from Western Digital; again, neither were provided.

HGST, which is owned by Western Digital, proved to be the most reliable hard disk drive manufacturer, with a failure rate of just 0.09%; 29,047 drives were deployed, and 27 died. Seagate had a similarly impressive AFR, at just 0.31%; 93,398 drives were deployed, and 292 drives died.

If hard disk drives are going to disappear, it will be very gradual, and not likely to happen any time soon. While hard drive shipments fell by 14% in Q1 from Q4 of 2019, the ongoing Covid-19 pandemic is likely the main factor behind this. As larger capacity hard drives are manufactured – such as the 20TB models mentioned by Backblaze – it’s likely that they will be adopted in datacentres and servers.

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