[Users] affects of changing compatibility setting on running cluster

Hi everyone, I believe I need to change my cluster compatibility level and would like to know if I can do this ona live cluster or if I have to change everything to maintenance mode first. I ran engine setup and upgraded to current engine level then tried to add a new node using the 3.3.4 el6 iso. This resulted in an error: Host x.x.x.x is installed with VDSM version (4.14) and cannot join cluster Default which is compatible with VDSM versions [4.13,4.9,4.11,4.12,4.10]. My current versions are: Engine 3.3.4-1.el6 at compatibiltiy version 3.2 2 Nodes running CentOS 6.4 with VDSM 4.10.3-0.36.23.el6 Am I correct that I need to change the compatibility version to 3.3? This has some production VMs, do I need to turn everything off first or is this a non-interruptive change? How will this upgrade affect my current 2 hosts at their version? My original idea was to migrate working VMs to new ovirt ISO node and then re-install original nodes to the same version off the 3.3.4 el6 iso. I appreciate any advice. Chuck