Rancher in VMs - KVM

I am wanting to run Rancher in KVM VMs. Anything I should know? Any special settings that are essential or good to know about?

can t say anything about KVM but using ESX ist working fine.
I m using Centos 7 VMs installed with kickstart / pxe without any manual interaction.
My „big“ docker nodes are are metal installed with kicksart. A new installation needs 10 - 15 minutes. No need of backups etc. for nodes.