Programming Interface Information: The Monitor Records are intended Programming Interfaces that allow the customer to write programs to obtain services of z/VM.

#### MRIODCAD

Prolog
Control Block Contents
Cross Reference

#### MRIODCAD Prolog

####

####

     DSECT NAME - IODCAD
     FUNCTION - Map a Monitor record.
     LOCATED BY -
            Through the Monitor Control Area
     REFERENCED CONTROL BLOCKS -
            MRRECHDR    Monitor Record Header
     NAME - MRIODCAD
     DESCRIPTIVE NAME - Monitor Sample Record
                        Domain 6 - I/O Domain
                        Record 4 - Cache Activity Data
     DESCRIPTION - Records cache activities.  Generated for each device
                   that is attached to a caching control unit such as
                   a 3880 model 11, 13, 21, and 23, or a 3990 model 3.
                   Its purpose is to enable management of the paging
                   cache in the storage directors.
     NOTES:
      -- This record is generated only for base addresses, and not
         for paging addresses.
      -- Data in IODCAD_CALDATA depends on the type of device being
         monitored.  The IODCAD_STATUS code indicates what kind of data
         is in it.
      -- For the 3880 Model 11, only the storage director that
         owns the cache is recorded.
      -- This record is not created for the secondary of a PPRC
         pair.

    MRIODCAD Control Block Contents

    Offsets
    Dec Hex  Type       Len  Name (Dim)          Description

      0   0  Structure  264  IODCAD
      0   0  Character    0  IODCAD_MRHDR        Record header. See MRRECHDR for
                                                 details.
      0   0  Character   20  MRHDR
      0   0  Unsigned     2  MRHDRLEN            record length in bytes
      2   2  Unsigned     2  MRHDRZER            field of zeros
      4   4  Unsigned     1  MRHDRDM             domain identifier
      5   5  Unsigned     1  *
      6   6  Unsigned     2  MRHDRRC             record identifier
      8   8  Character    8  MRHDRTOD            Time at which this record was
                                                 built. In time-of-day (TOD) clock
                                                 format. See IBM System 370 XA
                                                 Principle of Operation for
                                                 explanation of format.
     16  10  Character    4  *
     20  14  Character    0  MRHDR_END           End of header
     20  14  Unsigned     4  IODCAD_RDEVSID      host subchannel I.D. number
                                                 defined at initialization
     24  18  Signed       4  IODCAD_STATUS       code pertaining to contents and
                                                 mapping of the IODCAD_CALDATA data
                                                 area: -2 = No data because an I/O
                                                 request to obtain cache
                                                 information exceeded an internal
                                                 timer value and was cancelled. -1
                                                 = No data because the device is a
                                                 potential SIE ASSIST device. 0 =
                                                 I/O Error in producing the record.
                                                 No data. 1 = data from one storage
                                                 director of a 3880. Mapped by
                                                 IODCAD_CALDSSC. 2 = data from both
                                                 storage directors of a 3880.
                                                 Mapped by IODCAD_CALDSSC. 3 = data
                                                 from a 3990 model 3 or 6, a 9394,
                                                 or a 2105. Mapped by
                                                 IODCAD_CALPSF.
     28  1C  Bitstring   40  IODCAD_CALSSS       Subsystem status, as returned by
                                                 the SENSE SUBSYSTEM STATUS
                                                 command. Layout and contents,
                                                 which depend on the device, are
                                                 described in the device's hardware
                                                 manuals. If the device returns
                                                 more than 40 bytes of subsystem
                                                 status, field IODCAD_CALSSS2
                                                 contains the additional status
     28  1C  Character    6  *                   Defined in device hardware
                                                 manuals (see above).
     34  22  Signed       2  IODCAD_PSFLEN       Length (in bytes) of performance
                                                 statistics which are stored in
                                                 IODCAD_CALPSF for this device. If
                                                 this field is zero, then the
                                                 performance statistics length is
                                                 96 bytes.
     36  24  Character   32  *                   Defined in device hardware
                                                 manuals (see above).
     68  44  Character  192  IODCAD_CALDATA      Data area. Contains status
                                                 and/or performance data. See code
                                                 in IODCAD_STATUS. Layout and
                                                 contents, which depend on the
                                                 device, are described in the
                                                 device's hardware manuals.
    260 104  Bitstring    4  IODCAD_CALSSS2      Additional subsystem status as
                                                 returned by the SENSE SUBSYSTEM
                                                 STATUS command. Layout and
                                                 contents, which depend on the
                                                 device, are described in the
                                                 device's hardware manuals.
    264 108  Character    0  IODCAD_END
    IODCAD_CALDSSC Status and performance data collected from a 3880 control
    unit. If IODCAD_STATUS = 1 data was collected only from the first
    storage director. IODCAD_CALSSC2 will not apply. If IODCAD_STATUS = 2
    data was collected from both storage directors.

    Offsets
    Dec Hex  Type       Len  Name (Dim)          Description

      0   0  Structure  160  IODCAD_CALDSSC
      0   0  Bitstring   80  IODCAD_CALSSC1      Subsystem performance data, as
                                                 returned by the SENSE SUBSYSTEM
                                                 COUNTS command for the first
                                                 storage director
     80  50  Bitstring   80  IODCAD_CALSSC2      Subsystem performance data, as
                                                 returned by the SENSE SUBSYSTEM
                                                 COUNTS command for the second
                                                 storage director. Applicable only
                                                 when IODCAD_STATUS = 2.
    IODCAD_CALPSF Status and performance data collected from a 3990 model 3
    or 6 a 9394 or a 2105. Applicable only when IODCAD_STATUS = 3.

    Offsets
    Dec Hex  Type       Len  Name (Dim)          Description

      0   0  Structure  192  *
      0   0  Character  192  IODCAD_CALPSF       Subsystem performance data, as
                                                 returned by the PERFORM SUBSYSTEM
                                                 FUNCTION, READ SUBSYSTEM DATA
                                                 (PERFORMANCE STATISTICS) CCW chain

    MRIODCAD Cross Reference

                          Hex           Hex
    Name                 Offset Length Value

    IODCAD                  0    264
    IODCAD_CALDATA         44    192
    IODCAD_CALDSSC          0    160
    IODCAD_CALPSF           0    192
    IODCAD_CALSSC1          0     80
    IODCAD_CALSSC2         50     80
    IODCAD_CALSSS          1C     40
    IODCAD_CALSSS2        104      4
    IODCAD_END            108      0
    IODCAD_MRHDR            0      0
    IODCAD_PSFLEN          22      2
    IODCAD_RDEVSID         14      4
    IODCAD_STATUS          18      4
    MRHDR                   0     20
    MRHDR_END              14      0
    MRHDRDM                 4      1
    MRHDRLEN                0      2
    MRHDRRC                 6      2
    MRHDRTOD                8      8
    MRHDRZER                2      2

    This information is
    based on z/VM V4R4.0.

    Last updated on 22 Jul 2003 at 15:04:23.

    Copyright IBM Corporation, 1990, 2003