System
AIX 4.3.2 - ADSM 3.1

Tape drive.
IBM 7337 DTL tape drive w/ 14 slots autochanger & barcode reader.

Requirements:
We only need to backup the SERVER for now (we have only 1 machine).
We need to do a FULL BACKUP to tape every night automatically. (total data
to be backup is 23 GB, about 112,000 + files).
After each night backup the tape needs to be put offsite. (even if the
backup tape is not full).
These nightly backup tapes can be rotated every 30 days, except the end of
month backup
We need to maintain each end-of-month backup tapes for 3 years.

Questions:
How to schedule backup for the above requirements ?
How does the db should be sized to handle 3 yrs retention for end-of-month
tapes
Can the db be backup with the end-of-month tape - so that it does not take
additional space on the server.

Thanks in advance  & have a happy holiday