/MEMBER_TIMEOUT=n ddcu:

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

    Specifies the timeout value to be used for a shadow set member.
    The specified device must be a member of a shadow set that is
    mounted on the system where the command is issued.

    The value supplied by this qualifier overrides the system
    parameter SHADOW_MBR_TMO for this specific device. Each member
    of a shadow set can be assigned a different MEMBER_TIMEOUT value.

    The valid range for n is 1 through 16777215 seconds.

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