5. OPERATION › 5.2 VCC Data Recording

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5.2 VCC Data Recording


VCC records VTOC and catalog data to a data set.  The VCCDATA
DD statement references this data set in the JCL that is used
to run VCC.  It must be a disk data set.  You can define it
using sample JCL member VCCALLOC in library
sharedprefix.MICS.CNTL.

The size of this data set is dependent on the number of DASD
devices and number of data sets to be scanned by VCC.
Generally, a z/OS system with about 900 DASD devices online
will use approximately 45 cylinders of space on an IBM 3390.

Note that if you run VCC with SERIALIZE=Y you will cause VCC
to issue an ENQ on SYSVTOC, which will raise a hardware
RESERVE on the device to all connected systems.  This will
cause a problem with VCC itself if VCC is in the process of
scanning the volume upon which the VCCDATA file is allocated
and output processing requires expansion into another extent.

Therefore, use a larger primary allocation and no secondary
allocation if you plan to operate with SERIALIZE=Y.

Detailed information on record layout can be found in the
following subsections:

    1 - VCC Data Record Layout
    2 - VCC-DFHSM Data Record Layout