[Beowulf] SSDs for HPC?
Ellis H. Wilson III
ellis at cse.psu.edu
Mon Apr 7 18:48:12 PDT 2014
On 04/07/2014 09:34 PM, Prentice Bisbal wrote:
>> Was it wear out, or some other failure mode?
>> And if wear out, was it because consumer SSDs have lame leveling or
>> something like that?
> Here's how I remember it. You took the capacity of the disk, figured out
> how much data would have to be written to it wear it out, and then
> divided that by the bandwidth of the drive to figure out how long it
> would take to write that much data to the disk if data was constantly
> being written to it. I think the answer was on the order of 5-10 years,
> which is a bit more than the expected lifespan of a cluster, making it a
This would be the ideal case, but requires perfect wear-leveling and
write amplification factor of 1. Unfortunately, those properties rarely
However, again, in the case of using it as a Hadoop intermediate disk,
write amp would be a non-issue because you'd be blowing away data after
runs (make sure to use a scripted trim or something, unless the FS
auto-trims, which you may not want), and wear-leveling would be less
important because the data written/read would be large highly
sequential. Wear-leveling would be trivial under those conditions.
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