Re: Hard drive lifetime: wear from spinning up or rebooting vs running

[David Liontooth <liontooth@cogweb.net>]

Mattias Wadenstein wrote:

> On Sun, 5 Feb 2006, David Liontooth wrote:
>
>> In designing an archival system, we're trying to find data on when it
>> pays to power or spin the drives down versus keeping them running.
>
> Hitachi claims "5 years (Surface temperature of HDA is 45°C or less)
> Life of the drive does not change in the case that the drive is used
> intermittently." for their ultrastar 10K300 drives. I suspect that the
> best estimates you're going to get is from the manufacturers, if you
> can find the right documents (OEM specifications, not marketing blurbs).

"Intermittent" may assume the drive is powered on and in regular use and
may simply be a claim that spindle drive components are designed to fail
simultaneously with disk platter and head motor components. 

Konstantin's observation that "disk die about evenly from 3 causes: no
spinning (dead spindle motor power electronics), heads do not move (dead
head motor power electronics), or spontaneusly developing bad sectors
(disk platter contamination?)" is consistent with a rational goal of
manufacturing components with similar lifetimes under normal use. 

> For their deskstar (sata/pata) drives I didn't find life time
> estimates beyond 50000 start-stop-cycles.

If components are in fact manufactured to fail simultaneously under
normal use (including a dozen or two start-stop cycles a day), then
taking the drive off-line for more than a few hours should
unproblematically extend its life.

Appreciate all the good advice and references. While we have to rely on
specifications rather than actual long-term tests, this should still
move us in the right direction. One of the problems with creating a
digital archive is that the technology has no archival history. We know
acid-free paper lasts millennia; how long do modern hard drives last in
cold storage?  To some people's horror, we now know home-made CDs last a
couple of years.

Dave






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