Just a short note:
When doing a “duplicate from active database” with a larger amount of channels you need to set the PROCESSES setting in your parameter file to a reasonable high value (i.e. 500). Otherwise the duplicate will fail with:
RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03002: failure of Duplicate Db command at 03/30/2012 13:56:22 RMAN-05501: aborting duplication of target database RMAN-12001: could not open channel ORA_AUX_DISK_60 RMAN-10008: could not create channel context RMAN-10003: unable to connect to target database RMAN-04006: error from auxiliary database: ORA-12537: TNS:connection closed