[asterisk-users] Newbie Asterisk: Disaster Recovery Proof Asterisk

[Lee, John (Sydney)]

I am planning to roll out Asterisk to some offices and I have been
thinking about how to disaster proof the box.

For the production box, of course, it will have RAID 1 disk drives and
2GB memory at least.

a) If the office burns down, there is nothing much I could do.
b) If it is software error, then good luck with the trouble-shooting.
c) If the hardware fails, then I could call for the vendor to come to
replace faulty hardware but this is going to take at least 2 to 4 hours
no matter how much you pay for the warranty.

It is because of (c) that prompts me to think about configuring a cheap
desktop as a hot box so that if the production box fails disastrously,
then I could simply move the PRI cable to the hot box and business
should continue.
However, this will require the production box daily copying (rsync) all
the changed files to the hot box.
Is this a good idea?  Or is there a better idea?  Or am I too paranoid?
What do you guys do out there?