QDISK | Back to Index page

| Prolog Control Block Contents QDISK 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.

QDISK Prolog | Top of page

     NAME       : QDISK control block for Virtual Disk in Storage
     DESCRIPTION: Q-Disk Control Block
     DSECT      : QDISK
     FUNCTION   : This control block maps the Qdisk block used
                  to define and manage a virtual disk in storage.
     LOCATED BY : MDIQDISK field of MDISK block for Vdisk
     CREATED BY : HCPQDKCR
     DELETED BY : HCPQDKDS
     RELOCATION CONSIDERATIONS : None

QDISK Control Block Content | Top of page

     QDISK DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      QDISK          Q-Disk Control Block
                 Vdisk definition fields
    0000    0 Dbl-Word     8 QDILOCK (3)    Vdisk I/O lock for this Vdisk
    0018   24 Dbl-Word     8 QDIIASIT       I-ASIT for this Vdisk
    0020   32 Character   24 QDISNAME       Address Space Name for this Vdisk
    0038   56 Signed       4 QDIIOCNT       Count of virtual I/Os to Vdisk
    003C   60 Bitstring    6 QDITOD         TOD value (used as Qdisk
                                            identifier)
    0042   66 Bitstring    1 QDIDFLGS       Vdisk Definition Flags
              1... ....      QDIFWRIT       X'80' QDIFWRIT First write to
                                            Vdisk has occurred
    0043   67 Bitstring    1 *              Reserved
                 Data specific to a channel program
    0044   68 Signed       4 QDIDATA (0)
                 CCW information
    0044   68 Bitstring   16 QDIDEFXT       Define Extent data (mapped by
                                            DEFXTNT DSECT in HCPQDL)
    0054   84 Bitstring    8 QDILOCAT       Locate data (mapped by LOCDATA
                                            DSECT in HCPQDL)
    005C   92 Bitstring    1 QDILAST        Last CCW opcode
                 Flags
    005D   93 Bitstring    1 QDIFLAGA       QDISK I/O Flags A
              1... ....      QDIFIRST       X'80' QDIFIRST First CCW
                                            processing complete
              .1.. ....      QDIDFXTU       X'40' QDIDFXTU Define Extent used
              ..1. ....      QDIRIPLU       X'20' QDIRIPLU Read IPL used
              ...1 ....      QDILOCU        X'10' QDILOCU Locate used
              .... .1..      QDIWRITE       X'04' QDIWRITE Writes allowed
              .... ..1.      QDIFRMAT       X'02' QDIFRMAT Formatting writes
                                            allowed
              .... ...1      QDIDIAG        X'01' QDIDIAG Diagnostics allowed
    005E   94 Bitstring    1 QDIFLAGB       QDISK I/O Flags B
              1... ....      QDIRD          X'80' QDIRD Read State
                                            established
              .1.. ....      QDIRDRP        X'40' QDIRDRP Read Replicated
                                            established
              ..1. ....      QDIWT          X'20' QDIWT Write state
                                            established
              ...1 ....      QDIDRDV        X'10' QDIDRDV Read Verify in
                                            effect
              .... 1...      QDIMEA         X'08' QDIMEA Microcode Erase
                                            Alert requested
              .... .1..      QDISBA         X'04' QDISBA Send Block Address
                                            requested
              .... ..1.      QDIUCP         X'02' QDIUCP Present unit check
                                            on paging error
    005F   95 Bitstring    1 QDIFLAGC       Last LOCATE op code -- FBA
                                            Emulation ONLY
    0060   96 Bitstring    4 QDIDGDAT       Diagnostic Control data
    0064  100 Signed       4 *              Reserved for future use
              00000024       QDIDATSZ       *-QDIDATA Data area size
                 Sense Information
    0068  104 Bitstring   32 QDISENSE       Sense data area
              00000020       QDISNSIZ       *-QDISENSE Sense data size
                 Snap Data Parameter List for HCPSAC related
                 soft abends
    0088  136 Dbl-Word     8 * (0)
    0088  136 Bitstring   16 QDISDPL        Snap data list
              00000010       QDISLSIZ       *-QDISDPL Snap list size
                 Accounting information
    0098  152 Signed       4 QDIATIM        Time of creation or last ACNT
    009C  156 Character    8 QDIACTNM       Account number of owner
              00000015       QDISIZE        ((*-QDISK+7)/8) SIZE IN DWS FOR
                                            FREE/FRET

QDISK Storage Layout | Top of page

    *** QDISK - Q-Disk Control Block
    *
    *     +-------------------------------------------------------+
    *   0 |                                                       |
    *     =                       QDILOCK                         =
    *     |                                                       |
    *     +-------------------------------------------------------+
    *  18 |                       QDIIASIT                        |
    *     +-------------------------------------------------------+
    *  20 |                                                       |
    *     =                       QDISNAME                        =
    *     |                                                       |
    *     +---------------------------+---------------------------+
    *  38 |         QDIIOCNT          |         QDITOD-           |
    *     +-------------+------+------+---------------------------+
    *  40 |   -(03C)    |:DFLGS|//////|                           |
    *     +-------------+------+------+                           |
    *     |                       QDIDEFXT                        |
    *     |                           +---------------------------+
    *     |                           |        QDILOCAT-          |
    *     +---------------------------+------+------+------+------+
    *  58 |          -(054)           |:LAST |:FLAGA|:FLAGB|:FLAGC|
    *     +---------------------------+------+------+------+------+
    *  60 |         QDIDGDAT          |///////////////////////////|
    *     +---------------------------+---------------------------+
    *  68 |                                                       |
    *     =                       QDISENSE                        =
    *     |                                                       |
    *     +-------------------------------------------------------+
    *  88 |                       QDISDPL                         |
    *     |                                                       |
    *     +---------------------------+---------------------------+
    *  98 |         QDIATIM           |        QDIACTNM-          |
    *     +---------------------------+---------------------------+
    *  A0 |          -(09C)           | A4
    *     +---------------------------+
    *
    *** QDISK - Q-Disk Control Block

QDISK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    QDIACTNM       009C
    QDIATIM        0098
    QDIDATA        0044
    QDIDATSZ       0064 00000024
    QDIDEFXT       0044
    QDIDFLGS       0042
    QDIDFXTU       005D 40
    QDIDGDAT       0060
    QDIDIAG        005D 01
    QDIDRDV        005E 10
    QDIFIRST       005D 80
    QDIFLAGA       005D
    QDIFLAGB       005E
    QDIFLAGC       005F
    QDIFRMAT       005D 02
    QDIFWRIT       0042 80
    QDIIASIT       0018
    QDIIOCNT       0038
    QDILAST        005C
    QDILOCAT       0054
    QDILOCK        0000
    QDILOCU        005D 10
    QDIMEA         005E 08
    QDIRD          005E 80
    QDIRDRP        005E 40
    QDIRIPLU       005D 20
    QDISBA         005E 04
    QDISDPL        0088
    QDISENSE       0068
    QDISIZE        009C 00000015
    QDISLSIZ       0088 00000010
    QDISNAME       0020
    QDISNSIZ       0068 00000020
    QDITOD         003C
    QDIUCP         005E 02
    QDIWRITE       005D 04
    QDIWT          005E 20

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:31:09 EDT.
Copyright IBM Corporation, 1990, 2020