Using SETOAM to direct objects to a specific device type for an object storage group

You can use a SETOAM statement to direct all objects for an Object or Object Backup storage group to a specific tape type by specifying the TAPEUNITNAME(device-type) parameter that is associated with the storage group.

The following are examples of directing objects to specific tape device types using the TAPEUNITNAME parameter of the SETOAM statement:

If 3490 is the TAPEUNITNAME parameter, then objects written to the subject Object or Object Backup storage group would all have this unit name recorded in the tape volume table. Objects written to the Object or Object Backup storage group would all be written to 3490 devices.
If the TAPEUNITNAME(3490) is changed to a new device type, such as TAPEUNITNAME(3590), OAM continues to write to the available usable tape volumes that are associated with the Object or Object Backup storage group using 3490 devices until an MVS scratch allocation is required. When an MVS scratch tape is required to handle an out-of-space condition for the Object or Object Backup storage group, that scratch tape is written on a device that is specified by the SETOAM TAPEUNITNAME statement for that group, which is 3590 in this example.
OAM continues to read the objects that were previously written on 3490 devices for the Object or Object Backup storage group so long as there is a 3490 device available for allocation at the time the read is requested.
Note: If a tape volume that was previously written on a 3490 device is entered into an ATLDS or MTL, that tape volume continues to be used as long as the ATLDS or MTL to which it was entered contains a compatible device.

See Using dynamic allocation for tape drives for information concerning compatible devices not being available to handle requests.