Upgrade Experiences Oracle RAC 12c

Dear all,

want to share some upgrade experiences when going from Oracle Grid/RAC 11g to 12c. Hoping that my experiences can make life easier for others.

We are dealing with Oracle Grid/RAC in a NetApp/NFS shared storage environment.

Based on the documents from the Oracle community here (and of course many SAP and MOS notes) we started our first test upgrade and faced two challenges:

• Upon the standard setup we added listeners facing our monitoring facilities – this reflects in the listener_networks spfile parameter. In our dbua based approach the actual upgrade failed – as i could observe the listener_networks parameter led to a syntactically wrong entry in the temporary initSID.ora file. Our solution: Remove listener_networks before the actual upgrade and re-apply after the upgrade.
• Using Oracle RAC 12c implies that “Direct NFS” is active by default. In our case it unvealed that the NFS export for oraarch was insufficient for DNFS – leading to an archiver stuck rather fast in the actual upgrade. Not really knowing what to do we interrupted the upgrade – very unpleasing. Our solution: Restore database (you also do backups before upgrades, don’t you?) – switch off DNFS – next try of the upgrade. Hint: Search MOS for “dnfs_off”. Our recommendation: Clarify the proper use of DNFS before upgrading.

As i said i’am hoping these info might save some time for other RAC users.

Stefan