
Offload System
User Reference
Connectivity Systems, Inc.—Copyright © 2006
Use Pursuant to Company Instructions
13-17
could be consolidated into a new version of perhaps 1 or 2 tapes, freeing
the five remaining tapes for other uses.
The Offload Version Copy function copies an offload version into
BIM-EPIC backup format. The Offload Version Copy function will copy
an existing backup version or an existing offload version.
Programs The offload system consists of the following four programs:
TSIDOFD selects datasets for offload and backup by creating
control statements for TSIDOFL.
TSIDOFL offloads or backs up selected datasets.
TSIDONL restores offload and backup datasets back to disk or
creates a listing of datasets on an offload tape.
TSIDOFC consolidates offload tapes and copies offload and
backup tapes.
High
Performance I/O
The BIM-EPIC offload system uses proprietary disk and tape I/O routines
that provide extraordinary high performance through the use of physical
I/O, maximum block sizes, and a single tape file. The offload system is
implemented automatically as soon as BIM-EPIC is activated and is fully
compatible with the prior offload system. All JCL, control statements,
program names, and procedures remain unchanged. This onload program
automatically recognizes and processes offload and backup tapes created
under the prior offload system. This process provides complete access to
existing offload and backup datasets. Prior offload systems include EPIC
4.14 and earlier.
!
WARNING:
Whenever an offloaded dataset is read, the tape-resident data is
temporarily copied to DSAD and then deleted when the dataset is
closed. This means that sufficient disk space must be available to
temporarily copy the data to the disk pool specified in the EDD. If
an insufficient space condition occurs while creating this
temporary disk file, BIM-EPIC allocation configuration options will
be used, for example, FRAG and alternate pools.
Note:Note:
The BIM-EPIC Start Track 1 feature is required to automatically access a
dataset that has been offloaded. The STRTRK configuration option is set
for this feature. When this feature is active, if a program opens a dataset
version that has been offloaded to tape, BIM-EPIC will automatically load
the version to a Start Track 1 disk area. Then, when the program closes
the version, this Start Track 1 disk area will be deleted. This process is
sometimes described as staging an offloaded version.
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