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 Top of page
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