In its last hard drive reliability report, Backblaze reported three models as not having failed once; However, we cannot take this to mean that these three models have absolute reliability, as there are also some warnings concrete for these three particular models, so let’s start from the beginning and see what the storage services company has to say about it.
Hard drive models that have never failed … yet
The models in question are the Separate ST6000DX000, the HGST HUH721212ALE600 and the Western Digital WUH721816ALE6L0. Of these, only Seagate drives have been heavily used for over two years, and the company has “only” collected data from 886 drives, a number that may seem large and good enough to draw a statistic, but it is ridiculous. out of the 177,935 units that were reviewed in that last report, so here we have two of the caveats we were talking about.
However, the company also reports that the performance of the Seagate this is still remarkable because they were used for 74 months on average with a lifetime failure rate of 0.92%. The units DEO Yes HGST were used for 3 and 21 months respectively, so their failure rates of 0% (WD) and 0.41% (HGST) could increase dramatically as these units age.
In any case, these failure rates are still low compared to the average. Backblaze said the annual failure rate for all hard drives fell from 0.81% to 1.01% from the previous year: “The increase is within our confidence interval, but it’s worth looking into the future because the older the hard drives, the more likely they are to fail” – the company said in the report, but did not attribute the increase in the failure rate to anything in particular.
SSD vs Hard Drives, which type of drive is most likely to fail?
Backblaze has also updated its comparison of hard drive failure rates versus SSDs, in this case not as storage units but as system units in which the operating system resides and drives. ‘other servers. The company said its first attempt at a comparison “It was unreliable because each type of unit was at a different stage in its life cycle”, For what “It took the bootable hard drives that were in use at the end of Q4 2020 and go back in time to see where their average age was and the days of use were the same as the average SSD.”
This led the company to review the hard drive boot drive information from late 2025 and found that “When we perform the review using the same unit models, the same average age and a similar number of days of use” the failure rate of hard drives is multiplied by 10, which ultimately makes it more or less double that of SSDs.
In short, in this comparison, we can draw the conclusion that hard drives fail about twice as much as SSDs when used as a server start-up unit, i.e. with a start-up time of 24 × 7 but with a use that never or almost never puts the unit to work at its maximum capacity, since as we mentioned before For this comparison, the units of the system were taken into account and not those used for massive data storage, which are always working.
