Device allocation

If a tape volume is inadvertently ejected from a tape library between job step setup processing and device allocation, the exit is invoked during device allocation to let the installation reenter the volume. This invocation occurs for the first or only volume of the request when there is no TCDB record or the volume is shelf-resident. The requested volume should be entered into the tape library in which it was resident during job step setup.

Note: Although there are circumstances in which the job may run successfully if the volume is entered into any tape library, it is recommended that the volume be entered into the library in which it was resident during job step setup.

Table 1 lists the contents of the exit input when a volume record does not exist in the TCDB.

Table 1. CBRUXVNL input during device allocation—No TCDB volume record
Parameter	Meaning
UXNVOLSR	Volume serial number
UXNWHERE	2 indicates device allocation processing
UXNERROR	1 indicates no TCDB record

Table 2 lists the contents of the exit input when a shelf-resident tape volume record exists in the TCDB.

Table 2. CBRUXVNL input during device allocation—Existing TCDB volume record
Parameter	Meaning
UXNVOLSR	Volume serial number
UXNWHERE	2 indicates device allocation processing
UXNERROR	2 indicates volume is shelf-resident
UXNGROUP	Storage group name
UXNUSEA	Volume use attribute
UXNWPROT	Write protection status
UXNCHKPT	Checkpoint volume indicator
UXNLOC	Volume location code
UXNSHLOC	Shelf location
UXNOWNER	Volume owner information
UXNCREAT	Volume record creation date
UXNENTEJ	Last entry or ejection date
UXNMOUNT	Last mounted date
UXNWRITE	Last written date
UXNEXPIR	Volume expiration date
UXNTDSI	Tape device selection information