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> Old hard drives that are no longer economical for more intensive service, supported by disk-handling robotics. I am with the author in that I do not think th

> Old hard drives that are no longer economical for more intensive service, supported by disk-handling robotics. I am with the author in that I do not think they are using older disks. From personal experience (working with petabytes of disk based storage), I would put money on the fact that AWS is not using stock off the shelf older disks and then powering them on/off as a method of storage. The last thing you want to do with an older disk (5+ years) is ever power it off. The chances of it coming back to life decrease rapidly with each cycle. Picture seized bearings, etc. Your best hope it to keep them continually moving, but never powered down for extended periods of time. Also, the GB/power/physical space required ratio does not make sense after X number of years. For example, you could replace 3 shelves of 1TB disks, with one shelf of 3TB disks. Yielding less power consumption in less physical space! When you are at scale, data centre space and power are big factors. For these reasons, I do not think they are using old stock disks. NOTE: Maybe they are using some custom make disks, but from what I know about standard disks, even enterprise, they do not like being powered on/off when they get old.

hga 13y ago
Emphasizing the above, the study a few years ago of disk drives at big HPC centers found that they don't follow a bathtub failure model. Rather, there are very few infant failures, and wear is noticeable starting in the range of 1-2 years in service.
- lmm 13y ago
  The google results I saw were more like an exponential curve, i.e. a memory-less distribution - which would mean old drives are just as reliable as new ones.
  - hga 13y ago
    The HPC paper struck me as a lot more detailed, rigorous and useful. I read the Google paper later (assuming we're talking about the same one, they came out at roughly the same time), and the only useful takeaway I got from it was that disk companies seem to have solved moderately high temperature issues, Google actually saw a correlation with longer life and higher temperatures.

hga 13y ago

Emphasizing the above, the study a few years ago of disk drives at big HPC centers found that they don't follow a bathtub failure model. Rather, there are very few infant failures, and wear is noticeable starting in the range of 1-2 years in service.

lmm 13y ago
The google results I saw were more like an exponential curve, i.e. a memory-less distribution - which would mean old drives are just as reliable as new ones.
- hga 13y ago
  The HPC paper struck me as a lot more detailed, rigorous and useful. I read the Google paper later (assuming we're talking about the same one, they came out at roughly the same time), and the only useful takeaway I got from it was that disk companies seem to have solved moderately high temperature issues, Google actually saw a correlation with longer life and higher temperatures.