Chris Hoogendyk schrieb:
>
>
> 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.
Nice summary, Chris.
Why not contribute stuff like this to the docs/Wiki?
Thanks, greetings, Stefan.
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