There's a little bit of culture clash going on here, I think :-)

On Tue, Aug 31, 2004 at 04:29:43PM -0400, Joe Konecny wrote:
> Even on Sat and Sun when I'm not
> there the tape is still over written with the latest data.

The *last* thing I would *ever* want to do is to overwrite my
most recent good backup.  What if the current backup fails? [*]
Then I've lost them both.  The very idea makes me cringe!  Given
a choice between (a) overwriting last night's backup and (b)
failing to take tonight's backup, I'd reluctantly choose the
latter.

Admittedly, your site's needs might be different from ours, such
that a choice that none of us would make, is the right one in
your case.

But really, I'd much prefer not to have to make that choice at
all -- neither (a) nor (b) is very appealing -- and Amanda, used
as we've described, gets me out of having to take either risk.

[*] System crash, bug in the backup system (Amanda or otherwise),
    the heads need cleaning, the tape goes bad, the data won't
    fit on the tape, an attempt to back up a file as it's being
    written leads to an inconsistent image on the tape, or any of
    a dozen other failure modes, many of which are orders of
    magnitude more likely than a disk crash.


> If Amanda does only copies the data to a holding area and
> we lose a drive on Sunday night I have massive problems.
> That's what I call a disaster

It's only a disaster if the holding "area" is on the same
physical drive as the live data.  So don't do that!  Besides the
robustness problem you've mentioned, it's also bad for backup
performance.  Put it on its own spindle.

--

|  | /\
|-_|/  >   Eric Siegerman, Toronto, Ont.        erics AT telepres DOT com
|  |  /
It must be said that they would have sounded better if the singer
wouldn't throw his fellow band members to the ground and toss the
drum kit around during songs.
        - Patrick Lenneau