Question : What are our options to upgrade our Master-Local setup from Aruba OS 6.1.3 to 6.3 when ?upgrading all Controllers at the same time is not feasible?
Environment Information : Any Mobility Controller, Aruba OS 6.1.3.x
Symptoms : Multi-Controller environment needs proper planning before upgrade to ensure minimal downtime and smooth operations.
Cause : It's highly recommended to have Master and Local Controllers on the same code, else it causes issues with configuration sync up and can cause delayed AP failover times between Controllers on different codes.
Resolution : The best recommendation is as per the release notes that is to upgrade all the Controllers simultaneously and to disconnect the Master-Local connectivity meanwhile. We could implement this with minimal downtime by copying the new Aruba OS to backup partition of all Controllers, schedule a downtime and reload all Controllers during the downtime.
If the local Controllers cannot all be upgraded at the same time, we could convert the locals to individual masters and upgrade each Controller when possible.
1) Convert Locals as individual Masters and upgrade the locals individually. Note that we should refrain from making any changes to the WLAN configuration on the Master Controller.