On 4/18/2013 7:01 PM, mathog wrote: > High end SATA and SAS disks claim MTBF values that work out to over 100 > years, and yet it is a common
Amazing isn't it. Disks that never fail! > observation that certain models fail at rates entirely inconsistent > with those values. For instance, > 75% of all drives of one model dead in < 6 years. (Cited by one poster > in this thread: > > https://groups.google.com/forum/#!topic/comp.unix.solaris/zQjoyc8T01Y > > ). Additionally, manufacturer warranties at best only go to 5 years, > which suggests the manufacturers > don't have a whole lot of faith in their MTBF values. > > Some of you have huge amounts of storage, how many disk models lasted > as long as their MTBF suggests > they should? (Personally we have only one set of disks that are still > consistent with the claimed MTBF, > a set of 6 Fibre Channel disks that came with a Sun server and are now > 10 years old - with no failures.) > > How do they come up with the MTBF values for disks anyway? Clearly it > is not based on watching a large > sample of disks for countless years! Statistical analysis (called a bathtub analysis). MTBF's are WAGs at best, and not well matched against empirical observation. > > Thanks, > > David Mathog > [email protected] > Manager, Sequence Analysis Facility, Biology Division, Caltech > _______________________________________________ > Beowulf mailing list, [email protected] sponsored by Penguin Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf _______________________________________________ Beowulf mailing list, [email protected] sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
