We are running CUCM 8.5 on UCS virtualized OS, I am planning to upgrate to 9.1.2. Is there any upgrade path other than Refresh Upgrade to avoid the hours downtime on each CUCM node.
Like do a fresh installation of CUCM 9.1.2, and restore the configuration from the old version to new version, not sure if that would be possible?
Thanks in advance.
No, there's no way to avoid the refresh upgrade, nor there is a way to take a config from 8.5 into 9.1(2).
You can always use the import/export function from BAT, but you'll need to do some manual work to make the files compliant.
You can go to 10.X and use prime collaboration deployment to migrate without downtime.