I have a small lab environment so I decided to test this myself, and was able to duplicate a database called ora1db to an instance called devdb on the same server. The instance devdb is NOT configured in Commvault, but the source is getting backed up (using 2 streams/channels) and so I scripted the restore to also use 2 streams/channels as well. I have created 3 text files:
Duplicate ORA1DB to DEVDB initfile.txt
Duplicate ORA1DB to DEVDB script.txt
Duplicate ORA1DB to DEVDB output.txt
That contain the init file (for the auxiliary instance) the script file (that I called from the RMAN session) as well the output file (that contains the entire RMAN session plus RMAN output.)
Let me know if this helps, and if you are able to run the duplicate.
Note that I did not have to add ANY of the ENV parameters into the RMAN script, and the 3rd party command restore ran as a single job ID in Commvault using both channels/streams to transfer the data.
Ernst F. Graeler
Applications and File Systems