On Wednesday 25 June 2003 07:30, Roberto Samarone Araujo (RSA) wrote:
>Hi,
>
> It it possible to use amanda to do diferential backups ? Are
> there any specific configuration ?
>
Amanda will do differentials AFTER amanda has done a full. This is so
that there is a baseline reference date established for that disklist
entry.
But I think you mis-understand how amanda works. Unlike the other
solutions, amanda tries to use about the same amount of tape every
night. And amanda will juggle the schedule about, moving the dates
of things up by sometimes as much as 5 days in trying to achieve
that, and given enough time in dumpcycles, will do pretty well at
this balanceing act. To recap:
dumpcycle: The number of days (or weeks) that amanda has to do a full
backup of each disklist entry in. A lot of folks run 7 days or 1
week.
runspercycle: In case you are doing a monday to friday only run
schedule, this tells amanda how many times amanda will be run in the
above 'dumpcycle' number of days. Businesses often set this to 5
since theres not much going on over the weekends.
runtapes: If you have a tape changer, this sets the number of tapes
amanda will be allowed to use per run.
tapecycle: The number of tapes in the rotating pool. Amanda will use
every tape in the pool until it has used them all, and will then
start to recycle them on an oldest first basis. This should be not
less than 2x runspercycle*runtapes plus 2 or 3 for comfort in knowing
that you have in fact at least 2 generations of full, level 0 backups
on everything in the disklist. You wouldn't want to ever get in the
situation where you were over-writing your only full backup of
something, and have a power failure while doing that entry's lavel 0
again.
Here at home, I'm useing 7, 7, 1, 28 settings. DDS2 tapes are cheap,
and I actually have about twice that many in stock.
Amanda has had enough time to arrive at a fairly consistent tape
useage of above 90% fill each night.
--
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz 512M
99.26% setiathome rank, not too shabby for a WV hillbilly
Yahoo.com attornies please note, additions to this message
by Gene Heskett are:
Copyright 2003 by Maurice Eugene Heskett, all rights reserved.
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