
Using Disk Processing
1-46 User Reference
Connectivity Systems, Inc.—Copyright © 2006
Use Pursuant to Company Instructions
When BIM-EPIC closes a dataset, it takes the buffer size into account.
Using the buffer size and the amount of space left in the extent,
BIM-EPIC determines if another extent is needed. If another extent is
needed, BIM-EPIC makes the allocation.
If VSE runs out of space when writing the buffered records, BIM-EPIC
checks the VSE Label Area for another extent. If an extent is not there,
BIM-EPIC will cancel the job. With BIM-EPIC, VSE finds the Space
Holder extent that BIM-EPIC placed there. VSE then reads the VTOC,
finds an expired dataset, and replaces the )DATASET VTOC entry using
the correct dataset name.
If the Space Holder extent is not necessary, the VTOC entry remains as a
Space Holder record. Since the entry indicates the dataset is expired, the
space can be used for any uncontrolled dataset at any time. BIM-EPIC
reuses Space Holder extents on an as-needed basis.
You may see Space Holder records in your VTOC listings. You may also
see an extra extent in the DSN Catalog entry for the version. Neither of
these conditions adversely affects processing.
When closing an output disk dataset, BIM-EPIC:
Determines whether the previously-described Space Holder
extent is required. If the Space Holder is required, a precautionary
extent is required. BIM-EPIC writes the Space Holder record,
updates the VSE Label Area with the new extent information, and
writes the extent information into the DSN Catalog entry for the
version.
Places the version in closed status in the DSN Catalog.
Passes control to VSE.
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