Releases a volume previously accessed with the EXCHANGE MOUNT command.

 Format
           EXCHANGE>  DISMOUNT   device-name[:]

 Prompt
           Device:  device-name[:]

Additional information available:

ParametersDescriptionQualifierExamples

 device-name[:]

      Specifies the name of the  device  to  be  dismounted.   You  can
      specify  a  physical  device name or a logical name assigned to a
      physical device name.   If  you  omit  a  controller  designation
      and/or  a  unit  number, they default to controller A and unit 0,
      respectively.  You can also specify the name of a virtual-device.

      The  DISMOUNT  command  closes  all  connections  that   EXCHANGE
      maintains  to the device.  This command does not affect the state
      of the operating system mount, the device remains mounted in  the
      VMS sense.

      Only foreign devices may be  dismounted.   An  implicit  DISMOUNT
      command is executed when EXCHANGE exits.

Additional information available:

/MESSAGE

 /MESSAGE
 /NOMESSAGE

      The /MESSAGE qualifier  controls  whether  or  not  EXCHANGE
      prints  a message which says that the volume was dismounted.
      The default is determined by the /MESSAGE qualifier  on  the
      EXCHANGE verb when EXCHANGE was activated.

      1.  EXCHANGE>  MOUNT/FOREIGN   MTA0:
          EXCHANGE>  COPY   MTA0:AVERAGE.FOR/VOLUME=DOS11   *
          EXCHANGE>  DISMOUNT   MTA0:

          The MOUNT command mounts the tape on the  device  MTA0:.   An
          EXCHANGE  COPY  command  is  used to transfer a file from the
          tape.  The DISMOUNT command releases EXCHANGE's access to the
          volume.  The volume is still mounted on the system, however.