On Tue, Dec 07, 2004 at 12:35:29PM -0500, Chris Loken wrote:
>
> Apologies if this has come up before. Couldn't find anything relevant.
> I'm talking about level 0 dumps (not incrementals). Using ait-3 tapes,
> GNUTAR (not linux "dump"), a tape library, 104GB holding disk and
> setting runtapes greater than 1 (I need to dump several tapes-worth of
> data). NO software or hardware compression. amanda-2.4.4p1-0.3E
>
> Amanda works great for me. These are efficiency questions - not critical
> problems.
>
> a) When backing-up multiple disks from a single client, amanda seems to
> dump and then write them to tape in order of increasing size. This can
> be inefficient. e.g. if you have filesystems that are 40GB, 40GB, 55GB
> and 55GB and write to 100GB tapes, amanda will use 3 tapes when the
> backup would fit on 2 tapes.
>
> b) amanda doesn't seem to know that it will run out of space on a tape.
> E.g. if I have two 65GB filesystems to dump to a 100GB tape, amanda will
> write the first and then start writing the second one and keep going
> until it hits the end of tape. It then puts in the next tape and
> rewrites which is great but a lot of time was wasted writing a file
> which wasn't going to fit on the first tape. I'm running amtapetype for
> myself right now but have been using a tape entry from the amanda faq
> that sets "length 108890 mbytes" (but there are two different ones for
> the same drive and tape; Sony SDX-700C and AIT-3).
>
> So, my questions are 1) is what I've described above true (seems to be
> for me) and 2) is there anything I can do (easily) to change this behaviour?
>
Checking the setting of your "taperalgo" parameter is in order.
A suitable setting for what you want might be "largest dump
in the holding disk that should fit the remaining tape space".
Probably named something like "largestfit", but DHMTI. :)
Note, this does not affect the order of dumping. Other parameters
do that. It only affects which, of the already completed dumps,
amanda will choose to tape next. It will not wait around for
one that fits.
--
Jon H. LaBadie jon AT jgcomp DOT com
JG Computing
4455 Province Line Road (609) 252-0159
Princeton, NJ 08540-4322 (609) 683-7220 (fax)
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