Re: [semi-OT] Data archiving (was Re: Query on adding a USB hdd)
On Fri, May 25, 2007 at 10:41:18AM +0200, Johannes Wiedersich wrote:
> Douglas Allan Tutty wrote:
> > No. I figure a CD is good for at least a year. Every year, I
> > pull the two netinst cds from the bank, take an SHA hash and compare it
> > with the written notes, then run something like cdck on them. So far,
> > my Woody CDs are fine. Funny enough, so is my woody floppy set (the
> > whole shebang set of 20 floppies) on Maxell floppies; needed for my 486
> > that doesn't boot from CD or run an installer after woody's.
> Wow, you seem to have a lot of spare time. How long does it take you to
> perform all these checks?
My backup set isn't that large so only an hour or so.
> I do backups to usb hard drives. They have 40GB to 120GB and it takes on
> the order of 1 minute / GB to diff -r them.
So how often to you fsck -c the filesystem so that it attempts to read
every block so that in turn the drive hardware can handle fading
sectors? Hard drives on a shelf aren't maintenance-free either.
> Considering lifetime and how often you're able to rewrite / reuse the
> media, they are cheaper per GB than CDs/DVDs.
True. However, for a small data set (under 1 GB) the need for three
copies means three hard drives. Using a hard drive and rewriting over
it means that you loose old archives.