thanks guys.

We have an 8.1.5 database on an NT Server. It is a 24x7 system, but updates occur only till 2 pm since those are our timings. The size of our database is about 25GB.

We plan to take a complete backup first & thereafter do incremental backups.
So should I go in for RMAN only? Or should I do the first full backup using the OS commands and use RMAN for the incremental backups? Is that possible?

Thanks
Lynn