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Re: Question to: Friday tape question - Top 10
2007-08-01 10:30:05
Stefan G. Weichinger wrote:
Patrick M. Hausen schrieb:
Hi!
On Wed, Aug 01, 2007 at 11:45:00AM +0200, Ralf Auer wrote:
thanks, but does this also mean, that in future times I have always to
put the tapes in ...-02-06-03-... order, or does *she* switch over to
02-06-03-04-05-01-02-03-04-05-06-01... automatically, so that the newest
tape is in fact added at the end of the list after one full cycle?
Amanda may reorder tapes to be used any time, anyway.
Set up a cron job that executes amcheck every morning and
sends you the ouput via email. It contains the information
which tape Amanda expects next.
Ralf, Patrick is correct:
Amanda tracks tape usage and tells you which tape to insert.
Either by running amcheck or 'amadmin <conf> tape', and the report mail
of amdump also contains that info.
just to clarify this a bit...
amanda doesn't re-order tapes. It takes them as they come (as you give
them to it), as long as they fit amanda's algorithm according to your
cycle. Rather than go over it all here, look at the wiki documentation:
<http://wiki.zmanda.com/index.php/Taper_scan_algorithm>.
With a tape library, amanda is not going to scan the whole library. It
is going to look at the current slot. If the tape in that slot is
acceptable according to the algorithm, it will use it. Otherwise it will
go on to the next slot until it finds an acceptable tape or runs out of
slots.
So, while amanda will tell you what tape it expects on the next run (the
least recently used one), it will take what you give it as long as it is
acceptable. It's not going to take that '06' and put it "back in order".
The order as far as amanda is concerned is according to the date the
tapes were written. The label is just a pattern you specify that amanda
will require a match on. The one time I lost a tape, it was
bio-daily-007. I labeled a new tape bio-daily-0072, put it in the
current slot, and let amanda use it. So my order now goes through 006,
0072, 008, etc. That just reminds me that it is a tape I replaced.
If you look at the tapelist file, you will see the dates that all the
tapes were last written to. If you do `amtape <conf> update`, amanda
will scan all the slots in your changer and you will see what you have
in every slot.
And, as others have said, having dumpcycle=runspercycle=tapecycle is not
good. I have 5,5,35, which gives me 6 weeks+ of full backups.
You are responsible for your tapes and your cycle, but amanda will
always do the right thing as best as it can and will keep you informed.
Running amcheck in the afternoon off cron will result in amanda sending
you an email if things aren't ready to go for the night backup. It will
tell you what it was expecting and exactly what was wrong. The report
amanda sends you after a backup tells you exactly what it did and what
tapes were used or if there were any errors with the tape. And, if you
come in in the morning and don't have an email report, and wonder what
the heck is going on, you can run amstatus and it will give you full
details of exactly what is going on, what has been completed, how far
along stuff is that is being done, and what is waiting to be done.
---------------
Chris Hoogendyk
-
O__ ---- Systems Administrator
c/ /'_ --- Biology & Geology Departments
(*) \(*) -- 140 Morrill Science Center
~~~~~~~~~~ - University of Massachusetts, Amherst
<hoogendyk AT bio.umass DOT edu>
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Erdös 4
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