Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

#### QDGBL

Prolog

Control Block Contents
QDGBL DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### QDGBL Prolog

     Name       : Virtual Disk in Storage Global Control Block
     Description: V-Disk Global Control Block
     DSECT      : QDGBL
     Function   : This control block maps the global V-Disk
                  control block for the system.
     Located by : HCPSYSCM - System Common Area
     Created by : HCPQDLIN
     Deleted by : none

#### QDGBL Control Block Content

#### QDGBL DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      QDGBL          V-Disk Global Control Block
                 Vdisk chain of MDISK blocks and allocation lockword
    0000    0 Dbl-Word     8 QDGALOCK (3)   Vdisk Allocation Lockword
    0018   24 Signed       4 QDGMDISK       First MDISK block for Vdisk
                 Fields for keeping track of limits (in blocks)
    001C   28 Signed       4 QDGSYSLM       Limit of total Vdisk allocation
    0020   32 Signed       4 QDGUSRLM       Limit of size of Vdisks DEFINEd
                                            by a user (using DEFINE)
    0024   36 Signed       4 QDGSYSCA       Total currently-allocated Vdisk
                                            blocks
    0028   40 Signed       2 *              Reserved
    002A   42 Signed       2 QDGCOUNT       Vdisk counter for addr. space
                                            name (increment and save)
    002C   44 Signed       4 QDGLKCNT       Total number of LINKs to all
                                            Vdisks (includes 1 for each
                                            DEFINEd VDisk)
    0030   48 Signed       4 QDGDISKS       Total number of existing Vdisks
    0034   52 Signed       4 QDGSYSLD       Default of QDGSYSLM
    0038   56 Signed       4 QDGUSRLD       Default of QDGUSRLM
    003C   60 Bitstring    1 QDGAFLAG       'A' flag byte
              1... ....      QDGASYSC       X'80' - SYSTEM CONFIG set syslim
    003D   61 Bitstring    1 * (3)          Reserved
              00000008       QDGSIZE        ((*-QDGBL+7)/8) SIZE IN DWS FOR
                                            FREE/FRET

#### QDGBL Storage Layout

    *** QDGBL - V-Disk Global Control Block
    *
    *     +-------------------------------------------------------+
    *   0 |                                                       |
    *     =                       QDGALOCK                        =
    *     |                                                       |
    *     +---------------------------+---------------------------+
    *  18 |         QDGMDISK          |         QDGSYSLM          |
    *     +---------------------------+---------------------------+
    *  20 |         QDGUSRLM          |         QDGSYSCA          |
    *     +-------------+-------------+---------------------------+
    *  28 |/////////////|  QDGCOUNT   |         QDGLKCNT          |
    *     +-------------+-------------+---------------------------+
    *  30 |         QDGDISKS          |         QDGSYSLD          |
    *     +---------------------------+------+--------------------+
    *  38 |         QDGUSRLD          |:AFLAG|////////////////////|
    *     +---------------------------+------+--------------------+
    *  40
    *
    *** QDGBL - V-Disk Global Control Block

#### QDGBL Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    QDGAFLAG       003C
    QDGALOCK       0000
    QDGASYSC       003C 80
    QDGCOUNT       002A
    QDGDISKS       0030
    QDGLKCNT       002C
    QDGMDISK       0018
    QDGSIZE        003D 00000008
    QDGSYSCA       0024
    QDGSYSLD       0034
    QDGSYSLM       001C
    QDGUSRLD       0038
    QDGUSRLM       0020

This information is based on z/VM V5R2.0. Last updated on 12 Apr 2006 at 17:19:06 EDT.
Copyright IBM Corporation, 1990, 2005