You can identify the Oracle session ID for an RMAN channel by looking in the RMAN log for messages with the format shown in the following example:
channel ch1: sid=15 devtype=SBT_TAPE
The sid and devtype are displayed for each allocated channel. Note that the Oracle sid is different from the operating system process ID. You can kill the session by specifying the sid in a SQL statement, but the commands are not the same as the operating system process kill commands.
You can specify the sid in the SQL statement ALTER SYSTEM KILL SESSION command. It takes two arguments (the sid printed in the RMAN message and a serial number), both of which can be obtained by querying V$SESSION. For example, run the following statement, where sid_in_rman_output is the number from the RMAN message:
SELECT SERIAL# FROM V$SESSION WHERE SID=sid_in_rman_output;
Then, run the following statement, substituting the sid_in_rman_output and serial number obtained from the query:
ALTER SYSTEM KILL SESSION 'sid_in_rman_output,serial#';
Note that this is no more effective than killing at the operating system level if the process is hung in the media manager.