As of March 31, 2019, Backblaze had 106,238 spinning hard drives in our cloud storage ecosystem spread across three data centers. Of that number, there were 1,913 boot drives and 104,325 data drives. This review looks at the Q1 2019 and lifetime hard drive failure rates of the data drive models currently in operation in our data centers and provides a handful of insights and observations along the way. In addition, we have a few questions for you to ponder near the end of the post. As always, we look forward to your comments.
Hard Drive Failure Stats for Q1 2019
At the end of Q1 2019, Backblaze was using 104,325 hard drives to store data. For our evaluation we remove from consideration those drives that were used for testing purposes and those drive models for which we did not have at least 45 drives (see why below). This leaves us with 104,130 hard drives. The table below covers what happened in Q1 2019.
Notes and Observations
If a drive model has a failure rate of 0%, it means there were no drive failures of that model during Q1 2019. The two drives listed with zero failures in Q1 were the 4 TB and 5 TB Toshiba models. Neither has a large enough number of drive days to be statistically significant, but in the case of the 5 TB model, you have to go back to Q2 2016 to find the last drive failure we had of that model.
There were 195 drives (104,325 minus 104,130) that were not included in the list above because they were used as testing drives or we did not have at least 45 of a given drive model. We use 45 drives of the same model as the minimum number when we report quarterly, yearly, and lifetime drive statistics. The use of 45 drives is historical in nature as that was the number of drives in our original Storage Pods. Beginning next quarter that threshold will change; we’ll get to that shortly.
The Annualized Failure Rate (AFR) for Q1 is 1.56%. That’s as high as the quarterly rate has been since Q4 2017 and its part of an overall upward trend we’ve seen in the quarterly failure rates over the last few quarters. Let’s take a closer look...
Read more: 2019 Update on Hard Drive Failure Rates: Seeing More Failures