BRBACKUP options - difference between rman_util, rman_stage and rman_disk?

Hi

I am trying to implement a brbackup solution utilizing Oracle rman via Tivioli Storage Manager.

From reading the documentation, if I use rman_util option this will also require use of backint to backup the non-database elements. It appears that the rman_stage and rman_disk options can be used which do not require use of backint which sounds desirable.

However, I cannot find any documentation to explain how these differ and how these work?

It appears that the rman_stage option may work with an external tape API but when I try and use this, it asks for remote_host and remote_user to be entered in the init<SID>.sap file. This suggests that it is trying to do some sort of remote copy rather than use the tape API (TSM for Databases in my case).

Please can anyone explain this better?

Thanks

Tom