Allocating a large VLS file

Document ID : KB000075038
Last Modified Date : 29/03/2018
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Introduction:
When allocating and formatting a VLS file for use with CA Ideal or CA Datacom/DB, the internal addressing configuration will dictate how large the VLS file can be. If the upper limit is exceeded, you could receive error messages like this from the VLSUTIL program:
DISK SPACE ALLOCATION IS GREATER THAN MAXIMUM ALLOWED. EXCESS SPACE IS WASTED
RUN CANCELLED. ERROR CODE IS 0212
Instructions:
In version 14.0, a new parameter was introduced for the FORMAT function - LIBFMT= {H | F}. This parameter identifies whether the block number is stored as a 2-byte value (parameter value H for halfword), or as a 4-byte value (parameter value F for fullword). If this is not specified, blocks will use the 2-byte format. The result, as specified in the CA IPC Implementation Guide:
With the old 2-byte block numbering format, the maximum amount of space that can be allocated to one VLS library is 60900 blocks. With the new 4-byte block numbering format, the maximum space limitation for the VLS library is 65,535 tracks.

Here is a table showing three common blocksizes, and the maximum number of blocks or tracks you can allocate, depending on whether you use LIBFMT=H, with its maximum number of blocks, or LIBFMT=F, with the maximum allocation of 65535 tracks (4369 cylinders):
BlockBlocksLIBFMT=HLIBFMT=F
Sizeper trackMax TrksMax CylsMax blocksMax TrksMax CylsMax blocks
1960282175145609006553543691834980
2000262342156609006553543691703910
400012507533860900655354369786420
To allocate and initialize this VLS file, you can use JCL like this below. Note that secondary allocations are not used with VLS files.
//FMTVLS01 EXEC PGM=VLSUTIL
//         INCLUDE MEMBER=IPCSTLIB
//         INCLUDE MEMBER=IPCDDOUT
//VLSFILE  DD DSN=YOUR.VLS.LIB,DISP=(,CATLG,DELETE),
//            UNIT=3390,VOL=SER=DASD04,
//            DSORG=DA,SPACE=(CYL,(2000))
//SYSIN    DD  *
 FORMAT BLKSIZE=4000,NAMELEN=24,LIBFMT=F
/*

 
Additional Information:
For more information on handling VLS files, please refer to the following documentation:
CA IPC version 15.1 DocOps:  Using Inter-Product Components (IPC)  > Maintaining the CA IPC System > VLS Utility (VLSUTIL)
CA IPC version 15.0 DocOps:  Using Inter-Product Components (IPC)  > Maintaining the CA IPC System > VLS Utility (VLSUTIL)
CA IPC version 14.02 Implementation Guide, in the section, "Maintenance › VLS Utility (VLSUTIL)"

As always, please contact CA Technologies support for CA Datacom if you have further questions.