CA Dynam for VSE User Guide

Direct Access File Independence Facility (VCKD)
System Restrictions
VCKD has been designed to be transparent and flexible from the user's point
of view. Nevertheless, the system's design does impose a few restrictions.
The following are not supported:
• Spanned unblocked records
• Trailer labels
• Physical IOCS (EXCP level)
If a user program utilizes extent processing, then the program must process
every extent.
For VCKD support to be active for a file, the programmer logical unit (SYS
number) must be assigned to an FBA disk before the file is opened.
Each partition that runs programs using VCKD must contain enough GETVIS
area to contain all input/output buffers and VCKD control blocks.
Activating VCKD
The activation procedure for VCKD is relatively simple and straightforward. All
required processing phases and supporting utilities are installed automatically
with the installation of CA Dynam/FI. Just follow these steps to activate the
Direct Access File Independence Facility for a particular file.
1. Specify VCKD(YES) in the DYNAM/FI option record. For more information,
see DYNAM/FI in the Programming Guide.
2. Allocate the new FBA DA file and create the required JCL. For more
information, see Allocating FBA Disk Files.
3. Create the new FBA file. For more information, see Creating FBA Disk
Files.
4. Ensure that each partition has enough GETVIS area to contain all VCKD
I/O buffers and file control blocks.
VCKD File Parameters
VCKD file parameters define the characteristics of the direct access file now
residing on the FBA disk. Each parameter is defined within the data set name
portion of the DLBL statement of the file. The specified parameters actually
become part of the data set name and must be specified at file creation.
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