as we are currently a routinge checkup of our infrastructure, we came across the need to migrate an existing UMP from an old standalone Windows Server 2008R2 to a two node CentOS7 installation for loadbalancing and HA considerations.
Our initial plan was to set up both new nodes alongside the old UMP and have them working as a three node configuration until the old UMP will be shut down.
But as I understand the tec-docs I've found this is would not really work as (some quite old guide states) all nodes need to be the same OS and even if it works with different OSes the shutdown of the primary (old) node would not result in one of the new nodes taking over as a new primary.
Is there any best practice on how to migrate UMP in this or a similar scenario? Has anyone perhaps acchieved what we are trying to do here?