/MVTIMEOUT=n DSAn:
       /MVTIMEOUT=n /ALL

    Note: Do not include any HBMM-specific qualifiers in a command
    with this qualifier; doing so causes the command to fail.

    Specifies the mount verification timeout value to be used for
    all shadow sets on the cluster or for the shadow set specified by
    its virtual unit name (DSAn:). The specified shadow set must be
    mounted on the system where the command is issued.

    The value supplied by this qualifier overrides the value
    specified by the system parameter MVTIMEOUT for this specific
    shadow set.

                                   NOTE

       You cannot change the value of MVTIMEOUT for a system disk.
       Any attempt to do so results in an error.

    The valid range for n is 1 through 16777215 seconds.

    The timeout value set by /MVTIMEOUT does not persist after the
    shadow set is dismounted.