I need some dumpcycle advise.

I have a 40 slot tape library.

I have 4 "sets" of backups.
(4 configs with different systems in each config, some going to drive 1
some going to drive 0) All the configs use the same tapelist files, so
they are kind of aware of each other.

Amanda runs every day.

Each set can use 1 or two tapes.
(I told it it could use two, but most the time it only uses one).

Monthly I remove all the tapes from the library, send them offsite, and
install fresh ones. (this could be changed in order to meet my goal)

I need dumpcycle settings that ensure that every time I pull the tapes,
that all the data from the entire month is there.

currently I have 

dumpcycle 20 days
runspercycle 20
tapecycle 40 tapes

Comments? Suggestions? 

-- 
Mike Taylor
Coordinator of Systems Administration and Network Security
Indiana State University.               Rankin Hall Rm 053
210 N 7th St.                           Terre Haute, IN.
SANS GSEC  http://www.sans.org/