--On Thursday, October 23, 2003 15:53:23 +0200 Toralf Lund <toralf AT
procaptura DOT com> wrote:
> Paul Bijnens wrote:
>
>> Toralf Lund wrote:
>>
>>> I'm thinking about using more than one tape, i.e. set "runtapes"
>>> parameter to a value > 1, for my updated archival setup. Is there
>>> anything special I need to keep in mind when doing this? Also, how do
>>> I set up runspercycle in this case? Is it the total number of tapes
>>> runspercycle * runtapes, or just runspercycle?
>>
>>
>> runspercycle does not need to be changed. The "runtapes" means that
>> for each run up to that number of tapes may be used (note: not "must").
>
>> You have to increase your tapecycle probably to cover the same
>> dumpcycle(s), because you'll burn twice as much tapes for each run.
>> (well, "burn", hopefully not litteraly).
>
> I'm still not sure I understand. If I have
>
> runspercycle 2
>
> and
>
> runtapes 2
>
> will amanda try to distribute the full dumps across 4 tapes, or just 2?
Well, technically your data could be spread over up to four tapes, but you are
only going to have one full backup of a single filesystem on one of the tapes
(assuming no promotions were made) and not on the others.
Increasing runtapes just gives amanda more room to write a single day's
backups, but it is a maximum, so if all the scheduled backups fit on one
tape then it won't use the second one until the next run.
Frank
> When I think about it, the first answer makes most sense, as the parameter
> otherwise ought to have been called "tapespercycle".
>
>>
>> The parameter "taperalgo largestfit" will help to fill the first
>> tape(s) to 100%. (New since amanda 2.4.3.)
>
> I'm using that already.
>
>>
>> This works better when also using:
>>
>> dumporder "SSSSSS" # as many S's as you have dumpers
>>
>> (or use "TTTTTT", which is a good approximation of SSSS, but optimises
>> the total runtime of your backups better; I use TTTTT).
>>
>> For a complete explanation why this works better, see:
>>
>>
>> http://groups.yahoo.com/group/amanda-users/message/46327
>
> This is very helpful indeed. Thanks.
>
> I've been wondering how I might avoid having the largest image left on the
> holding disk when the total size is only just larger than the tape (like you
> say, taperalgo often doesn't help), but never noticed this parameter, or the
> message you are
> referring to.
>
> --
> - Toralf
>
>
--
Frank Smith fsmith AT hoovers DOT com
Systems Administrator Voice: 512-374-4673
Hoover's Online Fax: 512-374-4501
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