We usually reuse the VMware hardware and (most importantly) file storage. Some additional hardware is required temporarily so you can build out initial Openshift nodes. The VMware nodes are decommissioned and converted to OSV nodes as the conversion goes along. With some kinds of file storage (cough NetApp) the conversion is zero copy, the VM literally stays where it is. With others we will copy to new NFS storage areas which will be provisioned on the same physical hardware.