public static VmSchema getVmSchema(ClusterCreate spec, String nodeGroup,
List<DiskSpec> diskSet, String templateVmId, String templateVmSnapId) {
NodeGroupCreate groupSpec = spec.getNodeGroup(nodeGroup);
VmSchema schema = new VmSchema();
// prepare resource schema
ResourceSchema resourceSchema = new ResourceSchema();
resourceSchema.name = "Resource Schema";
resourceSchema.cpuReservationMHz = 0;