The caller of the test volume eligibility function must PIN the
UCB before passing UCBPTR. For a complete description of UCB pinning,
see z/OS HCD Planning.
When the TVE function returns return code 0, the volume specified
with the VOLUME keyword is eligible to be mounted on the drive associated
with the MVS Unit Control Block specified with the UCBPTR keyword
for one of the following reasons:
- Both the volume and the device are defined to the same tape library.
- Neither the volume nor the device are defined to a tape library.
When the TVE function returns return code 4, the request has been
processed, but the volume is ineligible to be mounted on the specified
drive for one of the following reasons:
- The use attribute of the volume is SCRATCH.
- The volume is not library resident but the device is defined to
a tape library.
- The volume is library resident but the device is not defined to
the same tape library.