Backblaze: Hard drive failure rates continue to decline
In its annual report, cloud provider Backblaze shows which hard drives are reliable, which show weaknesses, and how failure rates are developing.
(Image: Backblaze)
Backblaze, a cloud storage provider, has published its annual report on hard drive failures. The report covers the entire year 2025 as well as long-term trends. With an analysis of over 337,000 hard drives, the company provides detailed insights into failure rates, reliability, and the performance of various models.
According to the company, the failure rate across all hard drives (average annual failure rate, AFR) decreased to 1.36 percent, compared to 1.55 percent in the previous year. In total, 943 drives failed in the fourth quarter of 2025, requiring technicians to replace an average of around 30 drives per day.
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The data shows that higher capacity hard drives are increasingly dominating: models with 14 to 16 TB accounted for over 52 percent of the devices in use. Particularly reliable models such as the Toshiba MG08ACA16TA with an AFR of 0.90 percent stood out. On the other hand, older models like the HGST HUH728080ALE600 with an AFR of over 10 percent showed significant weaknesses.
The analysis also highlights that failure rates strongly depend on age, capacity, and manufacturer. New 26 TB hard drives were integrated for the first time and showed an AFR of only 0.40 percent in the first quarter. Furthermore, the quarterly analysis shows fluctuations: while the AFR decreased to 1.13 percent in the fourth quarter, it was 1.55 percent in the third quarter.
Two drive types completed the past quarter without failures: the two Seagate drives ST8000NM000A (8 TByte) and ST16000NM002J (16 TByte). An older HGST drive and two further Seagate drives with 12 and 16 TByte had one error each. On the other hand, Backblaze recorded an AFR of more than 5 percent for Seagate with the 10 TByte hard drive ST10000NM0086.
Guidance
In previous years, Backblaze did not use server hard drives for its continuously running systems but rather inexpensive desktop hard drives. Today, however, the company buys almost exclusively high-quality server hard drives.
An assessment of how long an individual hard drive will function in a system cannot be calculated from the data. Nevertheless, the statistics offer guidance for selecting hard drives. The report also underscores the importance of regular backups, as technical improvements alone cannot guarantee absolute data security. The complete dataset is available on the Backblaze website. (ll)
