Online backup provider Backblaze has over 100 petabytes of storage spread across more than 34,000 hard drives. The company has shared some interesting reliability data based on those drives, including manufacturer-specific failure rates. Today, it published new information examining the correlation between failure rates and drive temperatures. In short, there isn’t much of one—at least not with most of the drives in Backblaze’s environment.
Backblaze’s data center is loaded with storage pods that house 45 drives each. These pods are generally populated with the same kinds of drives, and the cooling appears to be sufficient. Average drive temperatures range from 22-31°C, which is well within the acceptable range for mechanical storage. As one might expect, 7,200-RPM models typically have higher temperatures than 5,400-RPM ones.
For the most part, drive temperatures are unrelated to failure rates. Backblaze only found statistically significant correlations with four of 19 drive models. Among those, the worst offender was easily Seagate’s Barracuda LP 1.5TB:
Barracuda LP drives with temperatures below the average for that model failed at a rate of 15.6% annually, while those above the average had a 34.6% failure rate. Even this correlation was deemed to be weak, though. "There’s a lot of overlap between the temperatures of the failed drives and the temperatures of the working drives, so you can’t predict for sure which drives will fail," Backblaze says.
Backblaze also found a weak correlation between temperature and failure rates for the Barracuda LP 1.5TB’s 7,200-RPM sibling. The remaining two drives, the Barracuda 3TB and Hitachi Deskstar 7K2000, exhibited "very weak" correlations. In fact, the cooler Deskstar drives failed slightly more frequently than the warmer ones. Statistics nerds can consult the Backblaze blog post for a model-by-model breakdown of the data.
Backblaze’s drives run an atypical workload in well-cooled servers, so the results aren’t necessarily indicative of what folks might see in desktop systems. The WD Black hard drives in my main PC usually run around 42°C, which is hotter than the warmest drives in this study. I’m still encouraged by Backblaze’s results, though, and I suspect server admins will be particularly interested.