VRDCBLOK Back to Index page
 
Prolog 
Control Block Contents 
   VRDCBLOK DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This page documents intended Programming Interfaces that
allow the customer to write programs to obtain the services of z/VM.


  VRDCBLOK Prolog Top of page
 
 NAME       : VRDCBLOK
 DESCRIPTION: VIRTUAL/REAL DEVICE CHARACTERISTICS BLOCK
 DSECT      : VRDCBLOK
 FUNCTION   : THE VRDCBLOK CONTAINS 256 BYTES OF VIRTUAL AND
              REAL DEVICE INFORMATION, AS WELL AS VIRTUALIZED
              READ DEVICE CHARACTERISTICS DATA.
 LOCATED BY : USAGE DEPENDENT
 CREATED BY : HCPDVTDC
 DELETED BY : USAGE DEPENDENT
 RELOCATION CONSIDERATIONS : None
 COMMENTS   : ANY CHANGES TO THE FORMAT OF HARDWARE READ
              DEVICE CHARACTERISTICS DATA SHOULD BE REFLECTED
              TO THIS CONTROL BLOCK
 
 
  VRDCBLOK Control Block Content Top of page
 

 VRDCBLOK DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure VRDCBLOK VIRTUAL/REAL DEVICE CHARACTERISTICS BLOCK 0000 0 Bitstring 2 VRDCDVNO VIRTUAL DEVICE ADDRESS 0002 2 Bitstring 2 VRDCLEN VRDCBLOK LENGTH 0004 4 Bitstring 4 VRDCVDAT (0) VIRTUAL DEVICE DATA 0004 4 Bitstring 2 VRDCVCOD (0) VIRTUAL DEVICE CODE 0004 4 Bitstring 1 VRDCVCLA R*1 VIRTUAL DEVICE CLASS 0005 5 Bitstring 1 VRDCVTYP R*2 VIRTUAL DEVICE TYPE 0006 6 Bitstring 1 VRDCVSTA R*3 VIRTUAL DEVICE STATUS 0007 7 Bitstring 1 VRDCVFLA R*4 VIRTUAL DEVICE FLAG 0008 8 Bitstring 4 VRDCRCDT (0) REAL DEVICE DATA 0008 8 Bitstring 2 VRDCRCCO (0) REAL DEVICE CODE 0008 8 Bitstring 1 VRDCRCCL R*5 REAL DEVICE CLASS 0009 9 Bitstring 1 VRDCCRTY R*6 REAL DEVICE TYPE 000A 10 Bitstring 1 VRDCCRMD R*7 REAL DEVICE MODEL 000B 11 Bitstring 1 VRDCRLLE (0) REAL DEVICE LINE LENGTH 000B 11 Bitstring 1 VRDCCRFT R*8 REAL DEVICE FEATURE 000C 12 Bitstring 1 VRDCUNDV UNDERLYING DEVICE CODE FOR DEVICES THAT EMULATE OTHER DEVICE TYPES. VALID ONLY FOR CLASTAPE DEVICES. ZERO FOR ALL OTHER DEVICE CLASSES. VRDCUNDV Values for CLASTAPE devices .... .... VRDCTNAT X'00' Native non-emulation drive .... ...1 VRDCT120 X'01' 3590 128-TRK drive (B1A or B11) attached to 3590 A00/A50/A60 or 3592 J70 control unit, emulating 3490E .... ..1. VRDCTVTS X'02' 3490E virtual drive in a 3494 VTS tape library .... ..11 VRDCT121 X'03' 3590 128-TRK drive (B1A or B11) attached to 3591 control unit, emulating 3490E .... 1..1 VRDCT255 X'09' 3590 256-TRK drive (E1A or E11) attached to 3590 A50/A60 or 3592 J70 control unit, emulating 3590 B1A or B11 .... 1.1. VRDCT254 X'0A' 3590 256-TRK drive (E1A or E11) attached to 3590 A50/A60 or 3592 J70 control unit emulating 3490E .... 1.11 VRDCT384 X'0B' 3590 384-TRK drive (H11 or H1A) attached to 3590 A60 or 3592 J70 control unit, emulating 3590/B1x .... 11.. VRDCT383 X'0C' 3590 384-TRK drive (H11 or H1A) attached to 3590 A60 or 3592 J70 control unit, emulating a 3490E ...1 .... VRDCT512 X'10' 3592 512-TRK drive (J11 or J1A) attached to 3590 A60 or 3592 J70 control unit, emulating 3590/B1x ...1 ...1 VRDCT511 X'11' 3592 512-TRK drive (J11 or J1A) attached to 3590 A60 or 3592 J70 control unit, emulating a 3490E ...1 ..1. VRDCT896 X'12' 3592 896-TRK Model E05 drive attached to 3592 J70 control unit emulating 3590 B1x ...1 ..11 VRDCTENC X'13' 3592 896-TRK Model E05 drive emulating 3590 B1x, and enabled for encryption ...1 .1.. VRDCTEN2 X'14' 3592 1152-TRK Model E06 drive emulating 3590 B1x, and enabled for encryption ...1 .1.1 VRDCTEN3 X'15' 3592 2176-TRK Model E07 drive emulating 3590 B1x, and enabled for encryption 1111 1111 VRDCTUNK X'FF' Unknown emulation drive 000D 13 Bitstring 1 VRDCRDAF Real Device Additional Features 1... .... VRDCFCDS X'80' VRDCFCDS Supports dataset level FlashCopy ..1. .... VRDCFCFV X'20' VRDCFCFV Supports full volume FlashCopy .... .1.. VRDCXRCT X'04' VRDCXRCT XRC-Timestamping enabled .... ..1. VRDCEMRD X'02' VRDCEMRD Signifies RDEV info is emulated Set for devices where we provide emulated info for a VDEV which has no true RDEV (such as VDISK) .... ...1 VRDCDA4F X'01' VRDCDA4F Supports DIAG A4 SCSI format 000E 14 Bitstring 2 VRDCRSVD Reserved: Must be 0s for z/VM 5.3.0 and earlier CKD/ECKD dasd Read Device Characteristics (RDC) mapping (most other devices are similarly mapped) 0010 16 Bitstring 64 VRDCSTRT (0) START OF THE RDC DATA BYTES 0010 16 Bitstring 2 VRDCCUTY CONTROL UNIT TYPE (RDCCUID) 0012 18 Bitstring 1 VRDCCUMD CONTROL UNIT MODEL (RDCCUMN) 0013 19 Bitstring 2 VRDCDVTY DEVICE TYPE (RDCDVID) 0015 21 Bitstring 1 VRDCDVMD DEVICE MODEL (RDCDVMN) 0016 22 Bitstring 4 VRDFEAT (0) DEVICE / STORAGE DIR. FEATURES 0016 22 Bitstring 3 VRDCDVFE DEVICE FACILITIES SUPPORTED 0019 25 Bitstring 1 VRDCSDFE SUBSYTEM FEATURES SUPPORTED 001A 26 Bitstring 1 VRDCDVCL DEVICE CLASS CODE 001B 27 Bitstring 1 VRDCDVCO DEVICE TYPE CODE 001C 28 Bitstring 28 VRDDEVF1 (0) DEVICE SPECIFIC FIELD 1 001C 28 Signed 2 VRDCPRIM NUMBER OF PRIMARY CYLINDERS NOTE: For volumes with greater than 65,520 cylinders, VRDCPRIM will contain X'FFFE'. See VRDCCYLS below. 001E 30 Signed 2 VRDCTRKC TRACKS PER CYLINDER 0020 32 Bitstring 1 VRDCSECT NUMBER OF SECTORS 0021 33 Bitstring 3 VRDCTOTR TOTAL USABLE TRACK LINGTH 0024 36 Bitstring 2 VRDCHA LENGTH FOR HA AND R0 0026 38 Bitstring 1 VRDCMODE TRACK-CAPACITY CALCULATION MODE 0027 39 Bitstring 5 VRDMDFR (0) TRACK-CAP CALCULATION FACTORS 0027 39 Bitstring 1 VRDCMDFR TRACK CAPACITY CALCULATION CHGNED 0028 40 Signed 2 VRDCNKOV NON-KEYED RECORD OVERHEAD 002A 42 Signed 2 VRDCKOVH KEYED AREA OVERHEAD 002C 44 Signed 2 VRDCALTC ADDRESS OF FIRST ALTERNATE CYL 002E 46 Signed 2 VRDCALTR NUMBER OF ALTERNAME TRACKS 0030 48 Signed 2 VRDCDIG ADDRESS OF DIAGNOSTIC CYLINDER 0032 50 Signed 2 VRDCDIGN NUMBER OF DIAGNOSTIC TRACKS 0034 52 Signed 2 VRDCDVCY ADDRESS OF FIRST DEVICE CYLINDER 0036 54 Signed 2 VRDCDVTR NUMBER OF DEVICE SUPPORT TRACKS 0038 56 Bitstring 1 VRDCMDR MDR RECORD ID 0039 57 Bitstring 1 VRDCOBR OBR RECORD ID 003A 58 Bitstring 22 VRDDEVF2 (0) DEVICE SPECIFIC FIELD 2 003A 58 Bitstring 1 VRDCCUID CONTROL UNIT ID (RDCCUTYP) 003B 59 Bitstring 1 * (13) RESERVED 0048 72 Bitstring 1 VRDRCUC Real CU code 0049 73 Bitstring 3 * Reserved 004C 76 Signed 4 VRDCCYLS Number of primary cylinders 0050 80 Bitstring 11 VRDCPGID Real Path Group ID 005B 91 Bitstring 5 * Reserved 00000050 VRDCLNGC *-VRDCSTRT SIZE OF VRDC DATA FOR CKD DEVICE FBA dasd Read Device Characteristics (RDC) mapping *** BYTES DEFINED FOR FBA DEVICE IN VRDCSTRT 0010 16 Bitstring 32 VRDCFBA (0) ALL 32 RDC BYTES 0010 16 Bitstring 1 VRDCOPER DEVICE OPERATION MODES 0011 17 Bitstring 1 VRDCFBAF FBA DEVICE FEATURES 0012 18 Bitstring 1 VRDCFBAC FBA DEVICE CLASS 0013 19 Bitstring 1 VRDCFBAT FBA DEVICE TYPE 0014 20 Bitstring 28 VRDFBAD1 (0) - 0014 20 Bitstring 2 VRDCRCSZ PHYSICAL RECORD SIZE 0016 22 Bitstring 4 VRDCBKCG BLOCKS PER CYCLICAL GROUP (TRACK) 001A 26 Bitstring 4 VRDCBKAP BLOCKS PER ACCESS POSITION 001E 30 Bitstring 4 VRDCBKMA BLOCKS UNDER MOVABLE ACCESS 0022 34 Bitstring 4 VRDCBKFA BLOCKS UNDER FIXED ACCESS 0026 38 Bitstring 2 VRDCBKAA BLOCKS IN ALTERNATE AREA 0028 40 Bitstring 2 VRDCBKCE BLOCKS IN CE AREA 002A 42 Bitstring 2 VRDCBFLG NUMBER OF BUFFERED LOG BYTES 002C 44 Bitstring 2 VRDCATMI MINIMUM ACCESS TIME 002E 46 Bitstring 2 VRDCATMA MAXIMUM ACCESS TIME 003A 58 Bitstring 22 VRDFBAD2 - 0050 80 Bitstring 16 * Reserved Tape Read Device Characteristics (RDC) mapping *** BYTES DEFINED FOR TAPE IN VRDDEVF1 001C 28 Bitstring 28 VRDTAPE1 TAPE SPECIFIC RESERVED *** BYTES DEFINED FOR TAPE IN VRDDEVF2 003A 58 Bitstring 22 VRDTAPE2 TAPE SPECIFIC RESERVED 0050 80 Bitstring 16 * Reserved 00000060 VRDC00LN *-VRDCBLOK Version 0 Output buffer length 0000000C VRDC00SZ (*-VRDCBLOK+7)/8 Version 0 length in doublewords Extended Input/Output Area Notes : These fields are only valid if the value of VRDCVERS (on output) is X'01' or greater. 0060 96 Bitstring 32 VRDCIOFL (0) Start of Extended Input/Output 0060 96 Bitstring 1 VRDCVERS Version of DIAG210 Output - This field should be 0 on input. 0061 97 Bitstring 31 VRDCRSIO Reserved for future IBM use - This field should be 0 on input. Extended Output Area Notes : These fields are only valid if the value of VRDCVERS (on output) is X'01' or greater. 0080 128 Bitstring 2 VRDCRDEV Real Device Number 0082 130 Bitstring 1 VRDRRCC Condition codes if device can't be reserved 1... .... VRDSUPRR X'80' VRDSUPRR Does not support reserve/release .1.. .... VRDMDWOV X'40' VRDMDWOV Minidisk without the 'v' suffix ..1. .... VRDNFPDD X'20' VRDNFPDD Minidisk that is not a fullpack ...1 .... VRDFPNSB X'10' VRDFPNSB Fullpack/dedicated device without the SHARED bit on 0083 131 Bitstring 125 VRDCRSVE Reserved Space 00000100 VRDC01LN *-VRDCBLOK Version 1 Output buffer length 00000020 VRDC01SZ (*-VRDCBLOK+7)/8 Version 1 length in doublewords 00000100 VRDCLNGT (*-VRDCBLOK) Size of VRDCBLOK 00000020 VRDCSIZE (*-VRDCBLOK+7)/8 Doubleword size of VRDCBLOK
 
 
  VRDCBLOK Storage Layout Top of page
 
          
*** VRDCBLOK - VIRTUAL/REAL DEVICE CHARACTERISTICS BLOCK
*
*     +-------------+-------------+------+------+------+------+
*   0 |  VRDCDVNO   |  VRDCLEN    |:CVCLA|:CVTYP|:CVSTA|:CVFLA|
*     +------+------+------+------+------+------+------+------+
*   8 |:CRCCL|:CCRTY|:CCRMD|:CCRFT|:CUNDV|:CRDAF|  VRDCRSVD   |
*     +------+------+------+------+------+------+-------------+
*  10 |  VRDCCUTY   |:CCUMD|  VRDCDVTY   |:CDVMD| VRDCDVFE-   |
*     +------+------+------+------+------+------+-------------+
*  18 |-(016)|:CSDFE|:CDVCL|:CDVCO|  VRDCPRIM   |  VRDCTRKC   |
*     +------+------+------+------+-------------+------+------+
*  20 |:CSECT|     VRDCTOTR       |   VRDCHA    |:CMODE|:CMDFR|
*     +------+------+-------------+-------------+------+------+
*  28 |  VRDCNKOV   |  VRDCKOVH   |  VRDCALTC   |  VRDCALTR   |
*     +-------------+-------------+-------------+-------------+
*  30 |  VRDCDIG    |  VRDCDIGN   |  VRDCDVCY   |  VRDCDVTR   |
*     +------+------+------+------+-------------+-------------+
*  38 |:CMDR |:COBR |:CCUID|//////////////////////////////////|
*     +------+------+------+//////////////////////////////////|
*     |///////////////////////////////////////////////////////|
*     +------+--------------------+---------------------------+
*  48 |:RCUC |////////////////////|         VRDCCYLS          |
*     +------+--------------------+---------------------------+
*  50 |                       VRDCPGID                        |
*     |                    +----------------------------------+
*  58 |                    |//////////////////////////////////|
*     +--------------------+----------------------------------+
*  60
*
*** VRDCBLOK - VIRTUAL/REAL DEVICE CHARACTERISTICS BLOCK
          
*** Overlay for VRDCSTRT in VRDCBLOK
*
*     +------+------+------+------+-------------+-------------+
*  10 |:COPER|:CFBAF|:CFBAC|:CFBAT|  VRDCRCSZ   | VRDCBKCG-   |
*     +------+------+------+------+-------------+-------------+
*  18 |   -(016)    |         VRDCBKAP          | VRDCBKMA-   |
*     +-------------+---------------------------+-------------+
*  20 |   -(01E)    |         VRDCBKFA          |  VRDCBKAA   |
*     +-------------+-------------+-------------+-------------+
*  28 |  VRDCBKCE   |  VRDCBFLG   |  VRDCATMI   |  VRDCATMA   |
*     +-------------+-------------+-------------+-------------+
*  30
*
*** Overlay for VRDCSTRT in VRDCBLOK
          
*** Overlay for VRDDEVF2 in VRDCBLOK
*
*                   +-----------------------------------------+
*  38 ...        3A |                                         |
*     +-------------+                                         |
*     |                       VRDFBAD2                        |
*     |                                                       |
*     +-------------------------------------------------------+
*  50 |///////////////////////////////////////////////////////|
*     |///////////////////////////////////////////////////////|
*     +-------------------------------------------------------+
*  60
*
*** Overlay for VRDDEVF2 in VRDCBLOK
          
*** Overlay for VRDDEVF1 in VRDCBLOK
*
*                                 +---------------------------+
*     ...                      1C |                           |
*     +---------------------------+                           |
*  20 |                                                       |
*     =                       VRDTAPE1                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  38
*
*** Overlay for VRDDEVF1 in VRDCBLOK
          
*** Overlay for VRDDEVF2 in VRDCBLOK
*
*                   +-----------------------------------------+
*  38 ...        3A |                                         |
*     +-------------+                                         |
*     |                       VRDTAPE2                        |
*     |                                                       |
*     +-------------------------------------------------------+
*  50 |///////////////////////////////////////////////////////|
*     |///////////////////////////////////////////////////////|
*     +------+------------------------------------------------+
*  60 |:CVERS|                                                |
*     +------+                                                |
*  68 |                                                       |
*     =                       VRDCRSIO                        =
*     |                                                       |
*     +-------------+------+----------------------------------+
*  80 |  VRDCRDEV   |:RRCC |                                  |
*     +-------------+------+                                  |
*  88 |                                                       |
*     =                       VRDCRSVE                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 100
*
*** Overlay for VRDDEVF2 in VRDCBLOK
 
 
  VRDCBLOK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
VRDCALTC       002C
VRDCALTR       002E
VRDCATMA       002E
VRDCATMI       002C
VRDCBFLG       002A
VRDCBKAA       0026
VRDCBKAP       001A
VRDCBKCE       0028
VRDCBKCG       0016
VRDCBKFA       0022
VRDCBKMA       001E
VRDCCRFT       000B
VRDCCRMD       000A
VRDCCRTY       0009
VRDCCUID       003A
VRDCCUMD       0012
VRDCCUTY       0010
VRDCCYLS       004C
VRDCDA4F       000D 01
VRDCDIG        0030
VRDCDIGN       0032
VRDCDVCL       001A
VRDCDVCO       001B
VRDCDVCY       0034
VRDCDVFE       0016
VRDCDVMD       0015
VRDCDVNO       0000
VRDCDVTR       0036
VRDCDVTY       0013
VRDCEMRD       000D 02
VRDCFBA        0010
VRDCFBAC       0012
VRDCFBAF       0011
VRDCFBAT       0013
VRDCFCDS       000D 80
VRDCFCFV       000D 20
VRDCHA         0024
VRDCIOFL       0060
VRDCKOVH       002A
VRDCLEN        0002
VRDCLNGC       005B 00000050
VRDCLNGT       0083 00000100
VRDCMDFR       0027
VRDCMDR        0038
VRDCMODE       0026
VRDCNKOV       0028
VRDCOBR        0039
VRDCOPER       0010
VRDCPGID       0050
VRDCPRIM       001C
VRDCRCCL       0008
VRDCRCCO       0008
VRDCRCDT       0008
VRDCRCSZ       0014
VRDCRDAF       000D
VRDCRDEV       0080
VRDCRLLE       000B
VRDCRSIO       0061
VRDCRSVD       000E
VRDCRSVE       0083
VRDCSDFE       0019
VRDCSECT       0020
VRDCSIZE       0083 00000020
VRDCSTRT       0010
VRDCTENC       000C 13
VRDCTEN2       000C 14
VRDCTEN3       000C 15
VRDCTNAT       000C 00
VRDCTOTR       0021
VRDCTRKC       001E
VRDCTUNK       000C FF
VRDCTVTS       000C 02
VRDCT120       000C 01
VRDCT121       000C 03
VRDCT254       000C 0A
VRDCT255       000C 09
VRDCT383       000C 0C
VRDCT384       000C 0B
VRDCT511       000C 11
VRDCT512       000C 10
VRDCT896       000C 12
VRDCUNDV       000C
VRDCVCLA       0004
VRDCVCOD       0004
VRDCVDAT       0004
VRDCVERS       0060
VRDCVFLA       0007
VRDCVSTA       0006
VRDCVTYP       0005
VRDCXRCT       000D 04
VRDC00LN       0050 00000060
VRDC00SZ       0050 0000000C
VRDC01LN       0083 00000100
VRDC01SZ       0083 00000020
VRDDEVF1       001C
VRDDEVF2       003A
VRDFBAD1       0014
VRDFBAD2       003A
VRDFEAT        0016
VRDFPNSB       0082 10
VRDMDFR        0027
VRDMDWOV       0082 40
VRDNFPDD       0082 20
VRDRCUC        0048
VRDRRCC        0082
VRDSUPRR       0082 80
VRDTAPE1       001C
VRDTAPE2       003A
 
This information is based on z/VM 7.3.0 Last updated on 22 Jun 2022 at 15:59:26 EDT.
Copyright IBM Corporation, 1990, 2022