On Mon, 2006-02-06 at 18:12 +0100, Francois Barre wrote: > 2006/2/6, David Liontooth <liontooth@xxxxxxxxxx>: > > 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... A program called Spinrite can fix such floppies (have done several times for me. Even floppies I formatted just 15min ago and suddenly cannot be read in another computer. One swipe with spinrite and it worked 100%. It also can remagnetise and even exercise bad sectors on HDDs. I have tried this on about 20 working disks now, and it has found blocks that were hard to read on 4 of them. These were fixed using statistical recovery. After running it again a week later it found nothing wrong with the disk. http://grc.com/spinrite.htm PS: The website looks a bit suspect, but the program actually does work as advertised as far as I have found. PS: Seems it does not like some adaptec scsi cards, no matter what disk I tested it got read errors on every sector. Both disks and controllers works fine for booting Linux/Windows so I guess it's the scsi bios/dos interaction that is making problems for Spinrite. > > 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. I've seen cd's be destroyed just because of morning moisture. The up-side (reflective side) is often unprotected and _very_ sensitive to moisture. Imagine sprinklers going off in your offices, how much valuable data is on those cds you do not store in a safe? I have heard that some recovery companies can recover data from such damaged cds since the data is not stored in the reflective layer. But I imagine it is a very costly experience. - 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
