I have an existing ovirt 4.1 cluster to which I would like to add a new node. Do I need to install the exact Node version the other nodes are running on? Or is it ok to use the latest minor version for the node?
You can safely install a newer version like oVirt Node 4.2 as far as you keep your current Cluster compatibility version. I have personally tested it in production, it works perfectly.
Unfortunately, there's no community documentation on this but you can peek at the Red Hat Virtualization Life Cycle where you can find a compatibility matrix under paragraph Red Hat Hypervisor Upgrade and Support Policy.
To this day, oVirt Node 4.2 is backward compatible with Cluster level 4.1, 4.0 and 3.6.
You can safely install a newer version like oVirt Node 4.2 as far as you keep your current Cluster compatibility version. I have personally tested it in production, it works perfectly.
Unfortunately, there's no community documentation on this but you can peek at the Red Hat Virtualization Life Cycle where you can find a compatibility matrix under paragraph Red Hat Hypervisor Upgrade and Support Policy.
To this day, oVirt Node 4.2 is backward compatible with Cluster level 4.1, 4.0 and 3.6.