On 09/05/2012 06:34 PM, jdow wrote:
> On 2012/09/05 11:38, Todd And Margo Chester wrote:
>> On 09/04/2012 12:21 PM, Konstantin Olchanski wrote:
>>>> Cherryville drives have a 1.2 million hour MTBF (mean time
>>>> >between failure) and a 5 year warranty.
>>>> >
>>> Note that MTBF of 1.2 Mhrs (137 years?!?) is the*vendor's estimate*.
>>
>> Baloney check. 1.2 Mhrs does not mean that the device is expected

The bottom line is huge MTBF numbers are, by definition, baloney because 
they are calculations based on some information which is _definitely_ 
not actually tested since no manufacturer runs their components for 137 
years.  If there is one thing you _can_ be sure about it is that _no_ 
real hard drive will actually last that long!

Case in point:

I bought a bunch of WD RE2 drives a few years back.  They too had a MTBF 
of 1.2M hours and a 5 year warranty and all but one had failed within 5 
years.  I can also confirm that these failures were _not_ because they 
were running out of spec.  IIRC the max. temperature for any of them was 
37 C, and all were in server chassis mounted on a concrete floor.

If I were you I would assume _all_ components _will_ fail.  If that 
failure would make your life miserable, plan on having a spare.  In the 
case of HDs I would _always_ use RAID, and IME software RAID1 is very 
reliable.

Jeff