We can add, change, or delete trend columns depending on community interest. The “Q2Q Trend” column is short for quarter-to-quarter trend, i.e. So this time we’ve included a trend indicator in the table. If the sample size is below that, the failure rates can be skewed based on a small change in the number of drive failures.Īs noted previously, we use the quarterly numbers to look for trends. That works out to about 550 drives running the entire quarter. When looking at the quarterly numbers, remember to look for those drives with at least 50,000 drive days for the quarter. This table includes 17 different 3.5in drive models that were operational during the indicated period, ranging in size from 3TB to 8TB. We’ll begin our review by looking at the statistics for the period of Apthrough J(Q2 2017). We cover more about migrations later on, but first let’s look at the Q2 quarterly stats. In fact, we added 4,921 new drives and retired 4,286 old drives as we migrated from lower density drives to higher density drives. In Q1 we added over 10,000 new drives to the mix, so adding just 635 in Q2 seems odd.

Since our last report for Q1 2017, we have added 635 additional hard drives to bring us to the 83,151 drives we’ll focus on. Along the way we’ll share our observations and insights and as always we welcome your comments and critiques. We also look at how our drive migration strategy is changing the drives we use and we’ll check in on our enterprise class drives to see how they are doing. In this update, we’ll review the Q2 2017 and lifetime hard drive failure rates for all our current drive models. For the most recent hard drive reliability statistics, as well as the raw hard drive test data, visit Hard Drive Data and Stats.

Backblaze hard drive reliability 2017