MOUNT command

Use the MOUNT command to allow allocation of an I/O device to all job steps that require a particular volume without intervening de-mountings and re-mountings of the volume. Because the system must schedule MOUNT commands, there is a short delay between when you issue the command and when the volume is mounted.

In a JES3 complex, use the MOUNT command with great care. When a volume is to be mounted on a JES3-managed direct access device, you must enter a MOUNT command on each system in the complex that has access to the device. In addition, if you are requesting that a volume be mounted on a JES3-managed unit, you must also enter a JES3 mount command (*MODIFY,S,M=...). See z/OS JES3 Commands.

Once the system has executed a MOUNT command, the specified device becomes reserved and remains mounted and reserved until an UNLOAD or VARY OFFLINE command is issued. A reserved direct access volume can be assigned the USE attribute of PUBLIC, PRIVATE, or STORAGE. A reserved tape volume can be assigned the USE attribute of PRIVATE or PUBLIC.

If you need to nullify a scheduled mount before the system executes the MOUNT command, use the CANCEL command.

Note that the system will issue a mount message for a pre-mounted volume. However, the mount message will only appear on the job's JES Job Log and in the SYSLOG. It will not appear on the operator's console.