Backblaze Publishes Hard Drive Failure Rate for Q3 2016

Cloud back and storage provider Backblaze has published their Q3 2016 statistics of hard drive failure rates covering 67,642 drives from their data centres. While this is fewer by 1,171 drives compared to their Q2 2016 numbers, this is due to the fact that the company has swapped out several smaller capacity drives for larger 8TB Seagate models.

Their Q3 2016 report covers the period of July 1st through September 30 2016 and includes hard drive models from HGST, Toshiba, WDC and Seagate from 2TB through 8TB sizes. Only drives with 45 or more in use are listed.

The chart includes total drive count, hard drive failure count, sizes, drive days and annualized failure rate. Annualized failure rate is calculated with the formula ((Failures)/(Drive Days/365)) * 100. Even though the Seagate ST4000DM000 4TB drive tops the list in terms of highest drive failure count, it is also the longest running drive in the batch and has a significantly higher drive count than the rest so the annualized failure rate for it is only 3.18%. The highest annualized failure rate belongs to the WD60EFRX 6TB drive of which there had been 13 failures out of 451 and has an annualized failure rate of 11.31%.

Since Backblaze has done some drive migration from 2TB HGST and WDC drives replaced with 8TB Seagate drives, they have also crunched the numbers if the failure rate is at an acceptable rate considering it does not make economic sense for them to replace the reliably low hard drive failure rates of the existing 2TB HGST drives with a new 8TB Seagate drive that has a higher rate. The result is an acceptable 1.6% annualized failure rate in comparison to 1.66% of the combined count of 2TB drives it replaces.

For more information visit Backblaze.