VirtualDiskFlatVer2BackingInfo diskfileBacking = new VirtualDiskFlatVer2BackingInfo();
diskfileBacking.setFileName("");
diskfileBacking.setDiskMode(mode.toString());
diskfileBacking.setThinProvisioned(type==VirtualDiskType.thin);
VirtualSCSIController scsiController = getFirstAvailableController(VirtualSCSIController.class);
int unitNumber = getFirstFreeUnitNumberForController(scsiController);
VirtualDisk disk = new VirtualDisk();
disk.setControllerKey(scsiController.key);
disk.setUnitNumber(unitNumber);
disk.setBacking(diskfileBacking);