[Users] ovirt-engine service restart with running virtual machines?

Hello all, I deployed oVirt as management platform for virtual machines in one datacenter and now I'm trying to get it working with M$ ActiveDirectory. The oVirt engine runs on the same physical machine as host and there are running virtual machines. I successfully run "engine-manage-domains -action=add ...": and it wrote this: ... Successfully added domain XXXX. oVirt Engine restart is required in order for the changes to take place (service ovirt-engine restart). Manage Domains completed successfully ... Since there are running virtual machines on the host with the engine, I would like to know if it is possible to restart ovirt-engine without shutting down virtual machines and/or putting the host into maintenance mode. Next question is if it is possible to restart ovirt-engine without affecting other running hosts with VMs in the same datacenter which engine maintains. Thank you in advance for the reply. Regards, Adam