DASDID Control Statement

The DASDID control statements identify the devices in your installation and the paths to the processors they work with.

You need DASDID control statements to provide EREP with physical identifiers for the DASD in your installation that do not provide their own physical IDs. See Direct-Access Storage Devices (DASD) for these devices.

EREP uses these physical identifiers to determine the probable failing unit (PFU) for the system exception report series.

The DASDID statements define the different paths from processors to devices in much the same way as do SHARE statements:
  • You can use the DASDID statements to take the place of SHARE statements for the DASD subsystem exception reports.
  • You can include the SHARE statements for DASD when you run the system exception report series, but EREP ignores them and uses the DASDID information instead.

Set up the DASDID statements, before you request the system exception report series. See Setting up DASDID Controls for detailed directions on preparing DASDID controls.

Indicates

The paths from a processor through channels, storage control units and controllers to each drive.

Syntax

DASDID statement formats differ depending on whether the processor is running in 370 or 370XA mode.

The syntax of the 370 DASDID control statement is:

370 DASDID control statement

Read syntax diagramSkip visual syntax diagramDASDID CPU=nnnnnn,CH=xx,SCU=ss,,STR=ccuu
nnnnnn
Is a six-digit decimal CPU serial number.
xx
Is a two-digit hexadecimal number identifying the channel (CH) between this CPU and the storage control unit.
ss
Is the physical identifier of the storage control unit (SCU). Each SCU must have a unique ID number.
ccuu
Is a four-digit hexadecimal value representing the controller and unit address for each DASD string (STR). The DASD string is the set of eight unit addresses assigned to one controller (or pair of controllers):
cc
Is the number you assign, in the range of 01–FE, to each controller. Each controller must have a unique ID number; however, controllers with string switch and 3350s with alternate controllers should have only one ID number.
uu
Is the last two digits from the lowest address on the string. The second digit should be zero or eight.
The format of the 370XA DASDID control statement is:

370XA DASDID control statement

Read syntax diagramSkip visual syntax diagramDASDID CPU=Xnnnnn,CHP=xx,SCU=ss,,STR=ccdddd
Xnnnnn
Is a five-digit hexadecimal CPU serial number preceded by an X in the central processor (CP) identifier position.
xx
Is the two-digit hexadecimal number identifying the channel path identifier (CHP) between this CPU and the storage control unit.
ss
Is the physical identifier of the storage control unit (SCU). Each SCU must have a unique ID number.
ccdddd
Is a five- or six-digit hexadecimal value representing the controller device number for each DASD string (STR). The DASD string is the set of eight device numbers assigned to one controller (or pair of controllers):
cc
Is the number you assign, in the range of 01–FE, to each controller. Each controller must have a unique ID number; however, controllers with string switches and 3350s with alternate controllers should have only one ID number.
dddd
Is the lowest device number on the string.

Defaults

None.

If you omit DASDID statements, those DASD that do not provide their own physical IDs are identified on the reports only by device type.

Coding

  • DASDID must be the first word in the statement, followed by one blank and the CPU= keyword with its associated value.
  • The keywords on this statement are positional and must be separated by commas.

Notes

The combined number of distinct CPUs specified on all of your control statements cannot exceed 256.

Examples

The following sections give you examples:

  1. Setting up DASDID Controls describes how to set up DASDID control statements for your DASD subsystem.
  2. Checking Your DASDID Statements describes how to use the EREP messages file (TOURIST output) to make sure that your DASDID statements match your DASD subsystem configuration.
  3. DASDID Configuration Chart Notes describes how to use the notes that may accompany the DASDID configuration chart and their meanings.