Backup Strategy in Oracle RAC 11.2.0.3 on AIX7.1

Hi,
Oracle RAC (2 nodes) 11.2.0.3 EE on AIX7.1 + Standby database (non RAC database managed by dataguard) - Oracle Streams involved

I would like to know what should be the best backup strategy for our system:

• The FRA is on ASM (because it's a RAC...)
• TSM is taking File System backup only (we do not have the media manager to backup directly on tape)

• So, considering that the FRA is the recomended place for backupsets, should we first backup in FRA then backup the FRA on a file system (ACFS, I think, to share the location between all node in case we need to initiate the backup from the other node)