DS4LABEL Back to Index page
 
Prolog 
Control Block Contents 
   DS4LABEL DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.

 
  DS4LABEL Control Block Content Top of page
  




 DS4LABEL DSECT
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Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      DS4LABEL       Mapping for VTOC DSCB's
0000    0 Character   44 DS4DSNAM       Data set name For Format 4 DSCB,
                                        DS4IDFMT = c'4'.
002C   44 Character    1 DS4IDFMT       Format identifier
002D   45 Bitstring    5 DS4HPCHR       Highest address of a format 1
                                        DSCB
0032   50 Bitstring    2 DS4DSREC       Number of available DSCBs
0034   52 Bitstring    4 DS4HCCHH       CCHH of next available alternate
                                        trk
0038   56 Bitstring    2 DS4NOATK       Number of remaining alternate
                                        trks
003A   58 Bitstring    1 DS4VTOCI       VTOC indicators
003B   59 Bitstring    1 DS4NOEXT       Number of extents in the VTOC
003C   60 Bitstring    2 *              Reserved
003E   62 Bitstring   14 DS4DEVCT (0)   Device constants
003E   62 Bitstring    4 DS4DEVSZ       Device size
0042   66 Bitstring    2 DS4DEVTK       Device track length
0044   68 Bitstring    2 DS4DEVOV (0)   Keyed record overhead
0044   68 Bitstring    1 DS4DEVI        non-last keyed record overhead
0045   69 Bitstring    1 DS4DEVL        last keyed record overhead
0046   70 Bitstring    1 DS4DEVK        Non-keyed record overhead differ.
0047   71 Bitstring    1 DS4DEVFG       Flag byte
0048   72 Bitstring    2 DS4DEVTL       Device tolerance
004A   74 Bitstring    1 DS4DEVDT       Number of DSCBs per track
004B   75 Bitstring    1 DS4DEVDB       Number of directory blocks per
                                        track
004C   76 Bitstring    8 DS4AMTIM       VSAM time stamp
0054   84 Bitstring    3 DS4AMCAT (0)   VSAM catalog indicator
0054   84 Bitstring    1 DS4VSIND       VSAM indicators
0055   85 Bitstring    2 DS4VSCRA       Relative track location of the
                                        CRA
0057   87 Bitstring    8 DS4R2TIM       VSAM volume/catalog match time
                                        stamp
005F   95 Bitstring    5 *              Reserved
0064  100 Bitstring    5 DS4F6PTR       Pointer to first format 6 DSCB
0069  105 Bitstring   10 DS4VTOCE       VTOC extent description
0073  115 Bitstring   25 *              Reserved
          0000008C       DS4END         *
         DSECT for VTOC DSCB Format 5 Records
      Bit mappings of unuseful flag bytes are not shown.
      Offsets for all DS5LABEL are based from start of key, not
      start of data.
 
 
  DS4LABEL Storage Layout Top of page
  
          
*** DS4LABEL - Mapping for VTOC DSCB's
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       DS4DSNAM                        =
*     |                           +------+--------------------+
*  28 |                           |:IDFMT|     DS4HPCHR-      |
*     +-------------+-------------+------+--------------------+
*  30 |   -(02D)    |  DS4DSREC   |         DS4HCCHH          |
*     +-------------+------+------+-------------+-------------+
*  38 |  DS4NOATK   |:VTOCI|:NOEXT|/////////////| DS4DEVSZ-   |
*     +-------------+------+------+------+------+------+------+
*  40 |   -(03E)    |  DS4DEVTK   |:DEVI |:DEVL |:DEVK |:DEVFG|
*     +-------------+------+------+------+------+------+------+
*  48 |  DS4DEVTL   |:DEVDT|:DEVDB|        DS4AMTIM-          |
*     +-------------+------+------+------+-------------+------+
*  50 |          -(04C)           |:VSIND|  DS4VSCRA   |(057)-|
*     +---------------------------+------+-------------+------+
*  58 |                   -DS4R2TIM                    |//////|
*     +---------------------------+--------------------+------+
*  60 |///////////////////////////|        DS4F6PTR-          |
*     +------+--------------------+---------------------------+
*  68 |-(064)|                   DS4VTOCE                     |
*     +------+             +----------------------------------+
*     |                    |//////////////////////////////////|
*     +--------------------+//////////////////////////////////|
*  78 |///////////////////////////////////////////////////////|
*     =///////////////////////////////////////////////////////=
*     |///////////////////////////+---------------------------+
*     |///////////////////////////| 8C
*     +---------------------------+
*
*** DS4LABEL - Mapping for VTOC DSCB's
 
 
  DS4LABEL Cross Reference Top of page
  
 
Symbol         Dspl Value
-------------- ---- -----
DS4AMCAT       0054
DS4AMTIM       004C
DS4DEVCT       003E
DS4DEVDB       004B
DS4DEVDT       004A
DS4DEVFG       0047
DS4DEVI        0044
DS4DEVK        0046
DS4DEVL        0045
DS4DEVOV       0044
DS4DEVSZ       003E
DS4DEVTK       0042
DS4DEVTL       0048
DS4DSNAM       0000
DS4DSREC       0032
DS4END         0073 0000008C
DS4F6PTR       0064
DS4HCCHH       0034
DS4HPCHR       002D
DS4IDFMT       002C
DS4NOATK       0038
DS4NOEXT       003B
DS4R2TIM       0057
DS4VSCRA       0055
DS4VSIND       0054
DS4VTOCE       0069
DS4VTOCI       003A
 
This information is based on z/VM 7.3.0 Last updated on 22 Jun 2022 at 15:49:56 EDT.
Copyright IBM Corporation, 1990, 2022