That would be totally down to your business requirements - how long do your management expect you to keep backups of their filesystems/databases for?

A basic config of daily incrementals & weekly fulls kept for a month, monthly fulls kept for a year may be ok for some but not others - it really does depend upon what's right for your business/management.

To reduce tape usage do not try to micromanage by having a lot of volume pools - e.g. "Monday AIX INCR" "Monday SQL FULL" etc etc etc - let NetBackup manage this for you. Keep volume pools to a minimum as much as you can.

 retention periods are generally defied by your company needs and requiremnets.

once you decide the rentection period for each type of backup , with your company or data owner. then you you need check how effective you can configure.

and this also require data size of each type of backup.

Thanks both of you. I will talke with our business team and also with the management. Data size is a important factor. Thanks.

In addition to previous excellent advice - media must be purchased to satisfy retention requirements.

Never adapt retention levels to cope with the amout of available tapes.