On Wed, Aug 23, 2006 at 09:43:14AM +0700, Olivier Nicole wrote:
> Hi,
> 
> Time to add my 2 cents to that thread, and ask for advice from Amanda
> gurus too.
> 
> The way I solvedthe offsite tapes thing is the following:
> 
> I declared:
> 
> dumpcycle 1 week
> runspercycle 5
> tapecycle 6 tapes
> 
> I labeled 6*3 tapes, with labels like set-1-00 to set-1-05, set-2-00
> to set-2-05 and set-3-00 to set-3-05. Only set-1 is marked for reuse,
> when I reach tape set-1-05, I mark all set-1 as no-reuse and set-2 as
> reuse. And etc.
> 
> This way I should have 2 complete cycle, including full and incr to be
> offsited.
> 
> Am I doing anything wrong? I find this much straight forward than
> having 2 configuration, one for full and one for incr.
> 

Nothing wrong.  Particularly if it works for you.

Some sites want only to offsite a set of full dumps.
A second config works well for this.

Others have a cost consideration for how many tapes
physically are offsited (can offsite be a verb? :)
I recall one poster saying the commercial storage
facility charged by the tape stored and extra for
each tape moved back and forth.

As you are rotating 18 tapes (3 sets of 6 each) and have 4 runs
per cycle, you really have a total of 3.6 "dump cycles" worth
of tape, not 3.

I'd worry about my schedule for no-reuse/reuse marking.  It is
not regular.  It would be after Monday (Tuesday) to start set 2,
then after Wednesday for set 3.  Set 1 starts again on a Friday.
Opps, that is after Friday, so on Monday.

What if you forget to do the remarking of the tapelist?  It will
go back to using tape 0 of the same set.

Perhaps have your cronjob automatically mark the tape used that
day "noreuse" and mark the 6th oldest one "reuse".

For you, what is the value of having 12 of your 18 tapes marked
"noreuse"?  Is it necessary to keep setting and resetting them?


When I backed up to DDS3 tapes, my changer had magazines that
held 6 tapes.  So I configured 6 runs/week, Saturday night was
skipped and Sunday night (actually Monday morning) collected
the 2 day weekend changes.  My "SOHO" network was so valuable
that of course I had to offsite tapes -- to my neighbors home :)
I changed magazines anytime over the weekend.

I kept 4 magazines in rotation.  Onsite were the one in use,
the one to be used next (oldest dumps), and the most recently
used for recovery of recent stuff.  Offsite was the one from
two weeks before.

Eventually my magazines no longer synchronized with the weekends
and I gave up the offsiting.  I'd change magazines when the report
said "dumps left in holding disk".  Or maybe a day or two later as
I had enought holding disk for over a week.

I think I still have some archive dumps (different config and
magazines) at my neighbors house.

-- 
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)