On Wed, Oct 09, 2002 at 04:53:55PM +0200, Toralf Lund wrote:
> >On Wednesday 09 October 2002 10:04, Toralf Lund wrote:
> >>I've never been quite able to figure out what value to use for
> >> tapecycle.
> >>
> >>I expect to run backups on first 4 days of week, so I've set
> >>    runspercycle 4
> >>
> >>Tapes are labelled
> >>Mon-1
> >>Tue-1
> >>...
> >>Mon-2
> >>...
> >>...
> >>Thu-4
> >>
> >>After the fourth "weekly set", the first one is reused, then the
> >> 2nd and 3rd. Set 4 is special, however - I don't want to reuse
> >> those tapes, but rather store them in a safe place and replace
> >> them with new ones. So after sets 1-4 are written, then sets 1-3
> >> once more, I want to be able to do
> >>
> >>amlabel ... Mon-4
> >>amlabel ... Tue-4
> >>
> >>without being told that those tapes are already active. What
> >> exactly do I set "tapecycle" to in order to allow this?
> >
> >You are trying to dictate to amanda, and that tends to be a hassle.
> >With the inevitable, often human error generated reruns,
> >(forgetting to change the tapes even after amanda sends you an

A situation for which I'm paying the penalty as I type.  Playing with
amflush to get the correct untaped dumps on to the "right" tapes so
my magazine rotation stays aligned with weekends.

> I think the real question is:
> 
> How does Amanda decide what tape to use next, and what tapes are 
> considered active, when there are more than "tapecycle" different labels?

Two separate situations to consider, initial startup and after amanda
has been running for a while.

During startup, amanda refuses to overwrite any tape until at least
tapecycle number of tapes have been used.  The order is whatever order
you insert them nightly.

After that, amanda will "expect" to use them in the same order in which
they were originaly seen.

However I believe amanda will accept "new" tapes beyond the tapecycle
number in lieu of the "expected" tape.  When their time comes around
in the order, the extra tapes will be "expected".  But I "think" amanda
will accept one from at least "tapecycle" dumps ago or a new tape again.

This leads to a suggested approach for which I have no experience
and thus no confidence it is a good or even viable approach.

set you tape label pattern to accept not just "Day-#", but something
like "Day-Archive-#" as well as the basic "Day-#".

set your tapecycle to 12, corresponding to Mon-1 to Thu-3.

On run 13, amanda will expect to return to Mon-1.  Give it Mon-Archive-1,
a new tape.  Same for the rest of the week.  Fifth week, return to Mon-1.
Eigth week, give amanda Mon-Archive-2.  Nineth week, back to Mon-1.

You may even be able to flag the filled archive tapes as "no-reuse".
I think this capability exists.  Don't "remove" the tape as I believe
this would also destroy the index files.


My feeling is that a separate config is just as easy.  And necessary
in my approach as I want a single amdump to give me a complete, though
multi-tape, archive.

-- 
Jon H. LaBadie                  [EMAIL PROTECTED]
 JG Computing
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 Princeton, NJ  08540-4322      (609) 683-7220 (fax)

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