However, after importing this via the VB Manager, and powering up the machine, I am unable to run oracles DBCA tool from the linux terminal window:
[oracle@localhost /]$ dbca
Exception in thread "main" java.lang.NoClassDefFoundError: oracle/sysman/assistants/dbca/Dbca
Caused by: java.lang.ClassNotFoundException: oracle.sysman.assistants.dbca.Dbca
at java.security.AccessController.doPrivileged(Native Method)
Could not find the main class: oracle.sysman.assistants.dbca.Dbca. Program will exit.
I have made no environmental changes to this, I even re-created a second VM, just to be sure of a completely vanilla installation, and tried running DBCA after powering it on for the first time, and I get the same issue.
Compared with a full install, the Oracle Developer Days pre-built VM is missing the folder dbhome_x/assistants. Not sure why? Maybe to save some space as these tools aren't used in the tutorials. Anyway, I copied the folder across from a real installation and dbca now works.