Programming Interface Information:
The Monitor Records are intended Programming Interfaces that
allow the customer to write programs to obtain services of z/VM.
Control Block Contents
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 ContentsOffsets 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 ReferenceHex 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 V4R3.0.
Last updated on 1 May 2002 at 16:20:33.
Copyright IBM Corporation, 1990, 2002