I assume that you are trying to create a clone on the same host where
the source database is residing with different oracle user name, if so I
was able to find a workaround trying in our lab.
1. Created a different user on the same host and associate with the
original dba group.
2. Changed the directory permissions of the source database mountpoints
such that the user and the group has the write permissions. (
-rwxrwxr-x)
3. Changed the Oracle datafiles permissions such that user and the group
has the write permissions. (-rwxrwxr-x)
4. Create a clone through SMO specifying the new user created in the
first step and it worked fine.
Note: The above changes mentioned in step 2 and 3 are not recommended by
any Oracle.
-Praveen.