writing one copy to tape instead of two

Hello,

We currently have three storage groups: primary stg NROBOT_DISK on disk, and we write two copies to primary stg ROBOT_TAPE, and secondary copy ROBOT_COPY (hich we send off-line).

Here is how it is defined :

tsm: TSM1>q stg NROBOT_DISK

Storage Device Estimated Pct Pct High Low Next Stora-
Pool Name Class Name Capacity Util Migr Mig Mig ge Pool
Pct Pct
----------- ---------- ---------- ----- ----- ---- --- -----------
NROBOT_DISK NROBOT_FI- 150,000 G 0.3 0.3 90 70 ROBOT_TAPE
ROBOT_TAPE LTO5 913,525 G 58.2 65.5 90 70
ROBOT_COPY LTO5 758,290 G 64.5

In a script, I backup up NROBOT_DISK and ROBOT_TAPE to ROBOT_COPY daily :

backup stg nrobot_disk robot_copy wait=yes
backup stg robot_tape robot_copy wait=yes


Now, in order to conserve tapes, we no longer whish to write to primary copy ROBOT_TAPE, but we would like to keep sending secondary tapes from ROBOT_COPY off-line. Here is what I thought of doing :

1) update stg NROBOT_DISK COPYSTGpools=ROBOT_COPY
2) remove the lines from the backup script
3) delete all volumes in ROBOT_TAPE with discarddata=yes
4) delete stg ROBOT_TAPE

Does this looks correct? No risk of dsmc re-backuping whatever was already in ROBOT_COPY a second time?

Thanks,

Andras