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 - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
