
LUB Allocation Additional BIM-EPIC Features and Functions
1-28 User Reference
Additional BIM-EPIC Features and Functions
LUB Allocation
VSE’s Logical Unit Block (LUB) connects the logical unit (SYS number) in a program’s file
definition (DTF) with the physical device (cuu) that controls the dataset.
The LUB allocation feature of BIM-EPIC assigns logical units for tape and disk devices if
they are opened when the SYS number specified in the program is already in use. This
eliminates potential conflicts in SYS number assignments when:
• a program or job stream uses the same SYS number for two different datasets, and the
datasets are stored on two different DASDs or
• the requested SYS number is permanently assigned to another device
The LUB allocation feature reassigns new SYS numbers (LUBs) to both datasets, and
continues processing without interruption. In addition, LUB allocation allows BIM-EPIC to
write multiple extents for a single dataset on separate disk volumes to make full use of its disk
pooling feature.
When a dataset is opened, if its SYS number is already in use, BIM-EPIC selects an unused
SYS number. For disk datasets, it begins assigning SYS numbers with the number specified in
the DSKLUB configuration option. For tape datasets, it begins with the number specified in
the TAPLUB configuration option.
LUB allocation is automatic in most circumstances. In some cases, it is inhibited
automatically. You can also inhibit it using JCL parameters.
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