on Mon, Nov 03, 2003 at 10:41:15PM +1030, David Purton (dcpurton@chariot.net.au) wrote:
> On Mon, Nov 03, 2003 at 07:00:19AM -0500, Haines Brown wrote:
> > You say you want a "new backup system," and did not specify it should
> > be tape.
> >
> > I recommend that you consider an external USB drive for backups. It is
> > the cheapest method you could use in terms of cost/mb, and does not
> > run the danger of proprietary standards (I've got a bunch of old OS/2
> > DAT tapes I'd like to access, but that will not be easy, no longer
> > having the commercial software, etc.). With tapes, you are probably
> > stuck using the one machine that has the drive, while an external
> > drive can be moved to any machine.
> >
>
> mmm - thanks - I'll look into it.
>
> Tape is starting to look like a fairly ugly option in terms of cost,
> but two or three usb drives might indeed be a good option.
What's your threat model?
Nearline storage can be useful and convenient for rapid recovery of an
accidentally deleted file.
For recovering from a breakin, fire, (ex) employee sabotage, an airplane
crashing into your office, lightning strike, earthquake, flood, or other
catastrophic event, you're SOL.
If you need to recover a snapshot (or file) from 12 months ago, a
three-disk rotation isn't going to do much for you.
If you need a clearer image of what's at stake: consider that a number
of businesses in the World Trade Center had full back up redundancy...in
the other tower. Or in lower Manhattan. Or in midtown. All of which
were either destroyed, or at the very least, offline for days after the
attacks of September 11, 2001.
Several drives will get you off the ground for nearline backup, in the
near future. Consider what your storage growth pattern is (for most
firms, it's on the order of 50-100% annually), and how you need to
multiply storage requirements for backups (storage x redundancies).
Tape offers a higher initial cost for the tape unit itself. Incremental
cost of additional storage is very low ($15-20 for media), and media are
reusable. Capacities are relatively high (20-80 GiB). A good network
backup solution will include a staging area which can also provide
nearline backup capabilities.
I've used disk-based backup systems. They're great. Until you outgrow
capacity. At which point, adding additional capacity means breaking
down your current array, losing history, and a day or more's backups
downtime while working out the kinks.
I'll recommend tape.
Peace.
--
Karsten M. Self <kmself@ix.netcom.com> http://kmself.home.netcom.com/
What Part of "Gestalt" don't you understand?
Backgrounder on the Caldera/SCO vs. IBM and Linux dispute.
http://sco.iwethey.org/
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