On Mon, Oct 16, 2006 at 09:33:21AM -0400, Lennart Sorensen wrote: > On Fri, Oct 13, 2006 at 10:51:56PM -0400, [EMAIL PROTECTED] wrote: > > I'm reviewing/planning for new offsite backup media and am wondering > > what people are using now. Previous discussions I found on > > lists.debian.org are a few years old. > > > > At this point, I'm specifying a backup-set size of 10 GB although if the > > media I choose is cheap enough, I would like to backup CD ISO images to > > protect that data from CD scratches or other failure. > > > > Physical size: A Zip jewel case is 4-1/8" and fits the bank, a CD jewel > > case is 4-3/4" and doesn't. > > > > Minimum number of backup sets, 3: one in the drive, one on the shelf, > > and one in the bank.
> > I want physical robustness. CDs are prone to scratch and I understand > > that for all they're 'burned' with a laser there is some dye involved in > > the process and they can fade in bright light or heat. Able to > > withstand a 1 m drop would be good, e.g. after its removed from its case > > and before it gets into the drive. > > > > 10 year shelf life seems to be a common criteria for backup/archive > > media. > > > Is backing up to a USB connected hard disk not rugged enough? The ones > using laptop drives should be fairly durable, and rather small in size > too. The drive caddies that go inside the case don't make much sense > for this unless it was a hotplug cage for sata or something. > Unfortunately linux does not yet support sata hotswap, although most > sata controllers can support it. eSATA would even be handy for that if > linux had support for that. One way to backup in such a case would be > to connect a drive the same size as the raid1 you have, and add the > backup drive as a 3rd mirror to the raid, let it rebuild (remember to > reduce the max rebuild speed enough to not make the machine unresponsive > for normal use), and when done, drop the usb/other external drive from > the raid again, and you have a perfect mirror as of that moment. It > could even be made bootable if you install the boot loader on it too. > Great backup and disaster recovery since you have a copy of your drive. > Thanks, Len, The encased USB laptop drive option in where I'm leaning after last night's research. Looking at how fragile a DLT cartridge is (basically drop it and its broke/unreliable even if it looks ok) compared to several drive enclosures that say they protect the drive at 1 m onto concrete, it makes the point. I was especially interested to find that the cost difference between a DLT cartridge and a comparible disk drive is getting smaller all the time. One wonders how long tape will be cost-effective even for large-scale archiving. I had wondered about the shelf-life of hard drives compared to DLT but since so many big names are making disk-based virtual tape drives, it suggests that they are comparable. Not that I'm puting data on a media (tape, drive, whatever) and leaving it for 10 years. I'm keeping the data current by cycling media through attached-shelf-bank monthly. Critical data that always needs to be up-to-date I'll probably use USB sticks for. Those files are plain-text so that they can be read from any computer that can mount the USB stick. It seems that USB sticks/flash-drives are far more rugged than anything other than paper. What have you found? At this point, I hadn't considered using the raid1 system to mirror everything onto the drive but that does make a lot of sense at least for the base system to keep a working snapshot off-site. Since my MB has an eSATA port on the back, I would like to use it for the backup, although I also have USB and Firewire. What is it that is keeping eSATA from being hot-swapable? Is there an ETA on this? Len, have you written a book or anything? Thanks for your wisdom, Doug. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
