Oracle 11g upgrade to 12c using DBUA

I have been meaning to document the 12c upgrade process, so have got started by doing it the most simplest way possible - using the Database Upgrade Assistant. My setup was an amazon EC2 instance running redhat linux with binaries installed and a running 11g database. In another home was the 12c binaries installed and a running 12c database.


1. Go to the 12c $ORACLE_HOME/bin folder and launch the dbua (I'm assuming you have already setup your x-display):

2. Select Upgrade Oracle Database

3. The DBUA should list the databases that can be upgraded (my 12c database was down)

4. The DBUA will perform some checks

5. It will display the findings. Check them and correct if necessary

6. Check the options - I left mine as they were

7. Configure OEM as per your setup

8. You have the option to move the datafiles or the FRA as part of this upgrade

9. Now it will ask what you want to do with the Listener. I went through this twice.

a)I left the setting as it was (knowing I already had a listener setup for 12c - but it was down)

I later received an error message during the install:

b) I setup another listener

10. I opted to create an RMAN backup (you will see why later) to disk

11. Review the summary..

12. ..and off you go can expand the upgrade steps so can find out where it is

..At this point if a failure occurs..

a) If the installer process comes across an error that it can't resolve, the upgrade will be backed out by restoring the RMAN backup from step 10

b) I simulated a server failure by shutting down my EC2 instance in the middle of the upgrade. On starting the server, this is what I had to:
  • Change the /etc/oratab value back to the 11g home
  • Remove any references the the 11g database in the 12c ORACLE_HOME i.e listener/tnsnames/init files in dbs folder
  • Set my environment up for the 11g database
  • Using RMAN run the following:
    $> rman target / nocatalog RMAN> startup nomount; RMAN> alter database mount; RMAN> Restore database; RMAN> Recover database; RMAN> alter database open resetlogs;
  • Connect to the database and check the objects
13. Allow the upgrade to run and it will eventually finish

..confirmation to the unix prompt

14. Check the log/output

15. Confirm the DB is at 12c

16. The upgrade process using dbua does not create any CDB's or PDB's