On Mon, 2 Jun 2008, Jacqui Caren wrote:
> Finally one thing I learnt from my Cray days - *test* your backups
> will restore. When you actually need them is *way* to late to find
> they are full of holes!
I've been hurt by that.
Some years ago I maintained a system from which we took weekly
filesystem dumps and daily incremental tarballs.
I tested the tarballs automatically via the script, but I could only do
save-time verifies on any other dumps and they always verified OK. I
could only _properly_ test the dumps by doing a complete reinstall.
Every time I built or changed the machine, I took the dumps and checked
they installed OK.
Of course one day a disc crashed really badly and we needed a rebuild.
The recent dumps wouldn't reinstall; the older dumps wouldn't reinstall;
The original tested dumps from a couple or so years back were now
corrupt and also wouldn't install. The tarballs were only ever
incremental.
Well actually I did have some just-in-case tarballs from a couple of
months earlier and probably could have rebuilt the machine, though it
was then around 12 or 14 years old, so I declared it dead and waited to
see who screamed. Nobody too much, so we mothballed it for a few years
'just in case', then finally binned it.
If your data is impportant, try to have two different backup media _and_
two different methods/formats _and_ two different storage locations.
USB drives are usually in the same room/building as the machne they're
backing. Mine are also painfully slow.
An old PC with a big disc or two, networked in a room the other side of
a fireproof barrier is fairly cheap and effective. Maybe the garage
would be suitable, maybe the New York office. Whatever.
G.
--
Gordon Scott http://www.gscott.co.uk
Linux ... Because I like to *get* there today.
