I am running Oracle Oracle8i Enterprise on Aix 4.3 and have a catalog db as well as a target database for RMAN .
want to run RMAN in a batch mode . My scripts is pasted below .
The script name is rman.sh

rman target 'internal@testdb_test' \ rcvcat 'rman/rman@catdb_test' \ cmdfile '/test2/testdbk.cmd' msglog '/test2/testdebug.log' append

My Log file is below
Recovery Manager: Release - Production

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00554: initialization of internal recovery manager package failed
RMAN-04005: error from target database: ORA-01005: null password given; logon denied

It asks me for the internal password .

my oracle_sid is set to the target database .

What is the problem.