2006/2/6, David Liontooth <liontooth@xxxxxxxxxx>: > Mattias Wadenstein wrote: > > > On Sun, 5 Feb 2006, David Liontooth wrote: > > 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. > IMHO, a single start-stop cycle is more costy in terms of lifetime than a couple of hours spinning. As far as I know, on actual disks (especially 7200 and 10k rpm ones), spinup is a really critical and life-consuming action ; spindle motor is heavily used, much more than it will be when spin speed is stable. On our actual storage design, disks are never stopped (sorry for Earth...), because it doesn't worth spinning down for less than a couple of days. However, temperature has a real impact on heads, (incl. head motors), because of material dilatation on overheat. So cooling your drives is a major issue. > how long do modern hard drives last in cold storage? Demagnetation ? A couple of years back in time, there were some tools to read and then rewrite floppy contents to remagnet the floppy content. I guess it shall be the same for the drive : periodically re-read and re-write each and every sector of the drive to grant a good magnetation of the surface. I would not give more than 100 years for a drive to lose all its content by demagnetation... Anyway, in 100 years, no computer will have the controllers to plug a sata nor a scsi :-p. I guess a long-living system should not stay cool, and re-activate/check its content periodically... > we now know home-made CDs last a couple of years. I thought it was said to be at least a century... But with the enormous cost reduction operated in this area, it's no surprise the lifetime decreased so much. - 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
