Hello,
I am just about to upgrade the Oracle11 databases to Oracle12c. It seems that AIX 7.2 is causing an issue with running the upgrade script and the symptoms are here:
12.2.0.1 on AIX and dbupgrade
I am on AIX 7.2 with all the blows and whistles, IBM support helped me check the APARS and version and still the same, so there is no way this script will work apart from the workaround from the link above.
When is Oracle going to fix this? It's really embarrassing.
The official Oracle pages even fail to mention to start the database:
SQL> startup upgrade
https://docs.oracle.com/en/database/oracle/oracle-database/12.2/upgrd/toc.htm
Thanks,
Ryszard