def pause(rh):
    """
    Pause a virtual machine.

    Input:
       Request Handle with the following properties:
          function    - 'POWERVM'
          subfunction - 'PAUSE'
          userid      - userid of the virtual machine

    Output:
       Request Handle updated with the results.
       Return code - 0: ok, non-zero: error
    """

    rh.printSysLog("Enter powerVM.pause, userid: " + rh.userid)

    parms = ["-T", rh.userid, "-k", "PAUSE=YES"]
    results = invokeSMCLI(rh, "Image_Pause", parms)
    if results['overallRC'] != 0:
        # SMAPI API failed.
        rh.printLn("ES", results['response'])
        rh.updateResults(results)    # Use results from invokeSMCLI

    rh.printSysLog("Exit powerVM.pause, rc: " + str(rh.results['overallRC']))
    return rh.results['overallRC']