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.
      -- This record is not created for PAV Alias devices.

    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
      2   2  Unsigned     2  MRHDRZER
      4   4  Unsigned     1  MRHDRDM
      5   5  Unsigned     1  *
      6   6  Unsigned     2  MRHDRRC
      8   8  Character    8  MRHDRTOD
     16  10  Character    4  *
     20  14  Character    0  MRHDR_END
     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 Shark, a
                                                    9394, or 9696.
                                                    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 Shark. Applicable only when IODCAD_STATUS = 3.

    Offsets
    Dec Hex  Type       Len  Name (Dim)             Description

      0   0  Structure    0  *
      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 V5R2.0.

    Last updated on 10 September 2007 at 15:28:55.

    Copyright IBM Corporation, 1990, 2006