On Wednesday 09 October 2002 20:28, Jay wrote:

[and I snipped]

In looking over your amanda.conf, a couple of things are a bit 
foobar.  From your amanda.conf:

"dumpcycle 4 weeks"

This is a very long time for amanda to go thru the system making 
sure she has one full backup of everything in your disklist.  Most 
run this at 1 week, or 7 days, although a business user may want 
that to be a bit shorter just so there is less to play catchup with 
in the event you are forced to recover from the last full backup.  
A weeks worth of business transactions to have to repeat is 
drudgery that sexytaries have been known to quit over.

"runspercycle 4 weeks"

If amanda takes the weeks arguement as it takes it in terms of 
dumpcycle, this is a total of 28 runs in one of your very elongated 
dumpcycles, intimating that it will be run every nite.  Nothing 
wrong with the every night run, most of us do it.  Most situations 
would seem to want something in the line of 7 and 7 for the above 
pair of variables.  You may have to stretch it out to make it fit 
on the tapes, but given amanda's ability to try to equalize the 
amount of data taped each night once she gets into the rythm of 
things, you probably could take the size of the data after 
compression, divide that by runspercycle, and by adjusting 
runspercycle and dumpcycle so it uses about 3/4ths of a tape per 
run.

"tapecycle 25 tapes"

Here you have insufficient tapes for the elongated dumpcycle chosen 
as it would take a minimum of 28 tapes to satisfy the runspercycle 
above.  Amanda therefore has no tape she can use for the next 
backup unless you label at least 3 new tapes and increment the 
tapecycle to match.

25 tapes is normally enough, but I'd shorten both the dumpcycle and 
runspercycle until it both fits on the tape, and you have at least 
2 full dumpcycles worth of full backups on hand at any one time.  I 
haven't run into this, so I have no idea if amanda will reuse the 
oldest tape if you do nothing more than reduce the dumpcycle and 
runspercycle to match the tapecycle.  Its worth a try just for 
effects. :-)

Not having any idea of how much data you have to cover, what I would 
do is to reduce the dumpcycle and runspercycle in unison, first to 
14 days each, and let amanda play catchup with that for one 
dumpcycle or maybe two.   Watching the tape usage report amanda 
mails you, then reduce it one or 2 each cycle until she is using 
about 3/4ths of a tape every night.  With only a 46 gig drive here, 
part of which is an rsync'd mirror of my gateway machine, I'm only 
averageing about 50% usage per nightly run on DDS2 tapes.  At 4g 
rated capacity, its about 2gigs that actualy gets written to tape 
after compression.  And its all covered at least once a week.

Compression by the drive is pretty much a no-no as it hides the true 
drive capacity from amanda, besides, software compression can be 
far more efficient than the drives puny little RLL(2-7) encoder.  I 
have several entries in my disklist that regularly compress to less 
than 20% of their original size.  Do it on the clients even if they 
are slower than the server because you can parallel the clients, 
and reduce the network bandwidth to move the compressed data to the 
server at the same time.

-- 
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz  512M
99.17% setiathome rank, not too shabby for a WV hillbilly

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