public void suspendPoweredOnGuestVMs(ManagedObjectReference attachHostMoref)
      throws InvalidPropertyFaultMsg, RuntimeFaultFaultMsg {
    Map<ManagedObjectReference, Map<String, Object>> vms =
        getMOREFs.inContainerByType(
            attachHostMoref,
            "VirtualMachine",
            new String[] {"name", "runtime.powerState"},
            new RetrieveOptions());
    suspendedVMList = new ArrayList<ManagedObjectReference>();
    for (ManagedObjectReference vm : vms.keySet()) {
      Map<String, Object> vmProp = vms.get(vm);
      VirtualMachinePowerState vmPowerState =
          (VirtualMachinePowerState) vmProp.get("runtime.powerState");
      String vmName = (String) vmProp.get("name");
      if ((vmPowerState.equals(VirtualMachinePowerState.POWERED_ON))) {
        try {
          ManagedObjectReference taskmor = vimPort.suspendVMTask(vm);
          if (getTaskResultAfterDone(taskmor)) {
            System.out.println(vmName + "[" + vm.getValue() + "] suspended successfully");
            suspendedVMList.add(vm);
          }

        } catch (Exception e) {
          System.out.println(vmName + "Unable to suspend vm : " + vm + "[" + vm.getValue() + "]");
          System.err.println("Reason :" + e.getLocalizedMessage());
        }
      }
    }
  }
  /**
   * This method queries the Vmware vCenter server for sensor data.
   *
   * @param svc the monitored service
   * @param parameters the parameter map
   * @return the poll status for this system
   */
  @Override
  public PollStatus poll(MonitoredService svc, Map<String, Object> parameters) {
    OnmsNode onmsNode = m_nodeDao.get(svc.getNodeId());

    // retrieve the assets and
    String vmwareManagementServer = onmsNode.getAssetRecord().getVmwareManagementServer();
    String vmwareManagedEntityType = onmsNode.getAssetRecord().getVmwareManagedEntityType();
    String vmwareManagedObjectId = onmsNode.getForeignId();

    TimeoutTracker tracker = new TimeoutTracker(parameters, DEFAULT_RETRY, DEFAULT_TIMEOUT);

    PollStatus serviceStatus = PollStatus.unknown();

    for (tracker.reset();
        tracker.shouldRetry() && !serviceStatus.isAvailable();
        tracker.nextAttempt()) {

      VmwareViJavaAccess vmwareViJavaAccess = null;

      try {
        vmwareViJavaAccess = new VmwareViJavaAccess(vmwareManagementServer);
      } catch (MarshalException e) {
        logger.warn(
            "Error initialising VMware connection to '{}': '{}'",
            vmwareManagementServer,
            e.getMessage());
        return PollStatus.unavailable(
            "Error initialising VMware connection to '" + vmwareManagementServer + "'");
      } catch (ValidationException e) {
        logger.warn(
            "Error initialising VMware connection to '{}': '{}'",
            vmwareManagementServer,
            e.getMessage());
        return PollStatus.unavailable(
            "Error initialising VMware connection to '" + vmwareManagementServer + "'");
      } catch (IOException e) {
        logger.warn(
            "Error initialising VMware connection to '{}': '{}'",
            vmwareManagementServer,
            e.getMessage());
        return PollStatus.unavailable(
            "Error initialising VMware connection to '" + vmwareManagementServer + "'");
      }

      try {
        vmwareViJavaAccess.connect();
      } catch (MalformedURLException e) {
        logger.warn(
            "Error connecting VMware management server '{}': '{}'",
            vmwareManagementServer,
            e.getMessage());
        return PollStatus.unavailable(
            "Error connecting VMware management server '" + vmwareManagementServer + "'");
      } catch (RemoteException e) {
        logger.warn(
            "Error connecting VMware management server '{}': '{}'",
            vmwareManagementServer,
            e.getMessage());
        return PollStatus.unavailable(
            "Error connecting VMware management server '" + vmwareManagementServer + "'");
      }

      if (!vmwareViJavaAccess.setTimeout(tracker.getConnectionTimeout())) {
        logger.warn(
            "Error setting connection timeout for VMware management server '{}'",
            vmwareManagementServer);
      }

      String powerState = "unknown";

      if ("HostSystem".equals(vmwareManagedEntityType)) {
        HostSystem hostSystem =
            vmwareViJavaAccess.getHostSystemByManagedObjectId(vmwareManagedObjectId);
        if (hostSystem == null) {
          return PollStatus.unknown("hostSystem=null");
        } else {
          HostRuntimeInfo hostRuntimeInfo = hostSystem.getRuntime();
          if (hostRuntimeInfo == null) {
            return PollStatus.unknown("hostRuntimeInfo=null");
          } else {
            HostSystemPowerState hostSystemPowerState = hostRuntimeInfo.getPowerState();
            if (hostSystemPowerState == null) {
              return PollStatus.unknown("hostSystemPowerState=null");
            } else {
              powerState = hostSystemPowerState.toString();
            }
          }
        }
      } else {
        if ("VirtualMachine".equals(vmwareManagedEntityType)) {
          VirtualMachine virtualMachine =
              vmwareViJavaAccess.getVirtualMachineByManagedObjectId(vmwareManagedObjectId);
          if (virtualMachine == null) {
            return PollStatus.unknown("virtualMachine=null");
          } else {
            VirtualMachineRuntimeInfo virtualMachineRuntimeInfo = virtualMachine.getRuntime();
            if (virtualMachineRuntimeInfo == null) {
              return PollStatus.unknown("virtualMachineRuntimeInfo=null");
            } else {
              VirtualMachinePowerState virtualMachinePowerState =
                  virtualMachineRuntimeInfo.getPowerState();
              if (virtualMachinePowerState == null) {
                return PollStatus.unknown("virtualMachinePowerState=null");
              } else {
                powerState = virtualMachinePowerState.toString();
              }
            }
          }
        } else {
          logger.warn(
              "Error getting '{}' for '{}'", vmwareManagedEntityType, vmwareManagedObjectId);

          vmwareViJavaAccess.disconnect();

          return serviceStatus;
        }
      }

      if ("poweredOn".equals(powerState)) {
        serviceStatus = PollStatus.available();
      } else {
        serviceStatus = PollStatus.unavailable("The system's state is '" + powerState + "'");
      }

      vmwareViJavaAccess.disconnect();
    }

    return serviceStatus;
  }