On Mon March 31 2003 10:51, Bill wrote:
>I recently installed amanda on my network to backup a couple of my
> dev boxes.  I understand that a tape must be labelled by amanda
> to be used with the appropriate dump set, but when I follow the
> instructions in the doc, amdump errors out saying that it cannot
> overwrite the active tape. Does someone have more comprehensive
> instructions for labelling tapes and setting up a run?  My
> assumption is I am simply misconstruing the instructions at some
> point.
>
>Thanks
>
>-b

A: tapes must be labeled with individually identifiable labels
        eg: tape-01, tape-02 etc, where the 'tape' portion fits the
        "labelstr" regex pattern in amanda.conf.  Defaults to "DailySet1"
        so the labels then become "DailySet1-01", "DailySet1-02" etc
        unless you change that pattern in amanda.conf.

B: a tape will not be willingly re-used until amanda.conf's
        "tapecycle" tapes have been used before it becomes eligible for
        re-use.

Generally speaking, one should have sufficient tapes to allow a 5 to 
7 day dumpcycle, and enough to do a minimum of 2 dumpcycles in 
tapecycle.  Multiply accordingly if the tape size vs systems size 
is such that you must use runtapes set for more than 1.  This 
requires a changer robot or a human to change tapes on demand.  In 
the long run the robot is cheaper, it doesn't take coffee breaks, 
vacations, sick leave, etc. :)

Amanda will schedule (eventually, its takes her time to get the 
schedule fine tuned) the fulls vs the partials over that 5 to 7 day 
dumpcycle in an attempt to equalize the tape useage per nightly 
run.  Because of this, one should construct his disklist file 
entries with 2 things in mind, 1; each entry should be less than a 
full tapes worth because amanda cannot span a single entry over 
more than 1 tape (breaking into subdir entries for size control 
implies the use of tar, as dump cannot do that), and then 2; 
uncomment only about a tapes worth of entries per day until its all 
exposed, at which point you can probably forget her until she needs 
the robots magazines refilled.

If its consistently useing all of a tape & no changer is involved, 
then dumpcycle should be expanded a day, or bigger tapes obtained.  
Likewise if its only useing half a tape, then dumpcycle can be 
reduced, thereby gaining additional security in fewer tapes in the 
unlikely event of a recovery need.

Obviously if dumpcycle is expanded, then additional tapes will need 
to be labeled and added to the pool in order to maintain the 
minimum of at least 2 fulls on hand at all times.  You never want 
to get into the situation where a failed full overwrites the only 
good full you had, thats genuinely 'bad dog, no bisquit' country. 

HTH

-- 
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz  512M
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Copyright 2003 by Maurice Eugene Heskett, all rights reserved.