On Tue, Apr 06, 2004 at 12:12:05PM +0100, William Hargrove wrote:
> Hello All,
> 
> I would like to ask a general Amanda backup 'strategy' question here, given
> by backup 'goals' below. I have a configured and working Amanda set-up but I
> want to try and fit a backup policy that I believe is best suited to our
> site around Amanda.
> 
> I have an 8-tape (DLT 35/70gb each) auto changer library linked to Amanda
> via mtx, this works well.
> 
> I want to do a full backup of various file systems on a remote host once a
> week and then, ideally, incremental backups once a day to that same tape. At
> the end of a week's backup, the tape should switch. One week's backup is far
> less than a single tape's capacity.
> 
> I would like to be able to hold 8 weeks worth of backups on tape, that is
> one tape a week and then reuse the oldest tape.
> 
> I'm not sure this is possible with Amanda.. as I believe I can't append the
> daily incremental backups onto the same tape as the full backups. Is it the
> case that if I want to run Amanda every day that I would also have to use a
> tape every day, thus meaning the tapes in the library are all used after a
> week. I'm fixed in the number of tapes I can use and can't add/replace them,
> so they would get reused after a week and wouldn't provide much of a 'backup
> horizon'.
> 
> If this isn't possible does anyone have some suggestions? I was thinking I
> could do the incremental backups to a hard disk area on the tape server each
> night and then run Amanda once a week to archive the full backups plus the
> HDD incremental ones.
> 


Where is that "Top Ten Questions" document when you need it?

Amanda will not reuse a tape for a new run of amdump, fulls or
incrementals, until it cycles through "tapecycle" number of
tapes.  So you are correct, amanda will NOT append a second
amdump to a tape.  Amanda only overwrites tapes!

However, an amflush can overwrite a tape with multiple dumps
from the holding disk.  Thus collect as many amdumps as you
want with the tape offline.  Then amflush when you want to
tape them.

-- 
Jon H. LaBadie                  jon AT jgcomp DOT com
 JG Computing
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