We ran a LIBR BACKUP job to tape using the following TLBL;
// TLBL BACKUP,'BACKUP.BEFORE.PTF'
The job appearred to work, since the following CA Dynam T messages appearred;
CADT007I ****** LABEL BACKUP SYS006=7B4 004042 1 *BACKUP.BEFORE.PTF* CADT031I *CLOSED* BACKUP SYS006=7B4 004042 BACKUP.BEFORE.PTF BLK=0
but then an IBM message was displayed and the job abended;
BG 0000 0P71I SYS006 NOT ASSIGNED BG 0000 0S00I JOB SYBKBPTF CANCELED
Why?
By default, Dynam releases assignments at dataset close, so that resources, such as the tape drive, may be used more efficiently. However, some programs, such as IBM's LIBR in this case, may perform I/O after close.
This default can easily be overridden by using a Dynam 'TLBL option' to hold the assignment until EOJ.
In this case the TLBL would look like this
// TLBL BACKUP,'BACKUP.BEFORE.PTF,H'
Note the addition of an 'H' to the dataset name.