Function

To display the checkpoint definition.

This command has parameters you can use as a filtering technique to limit the type of information to search, or the amount of information to display. See Using filtering to control and display information for additional information.

Parameters

CKPTn

Displays the status of either the primary (CKPT1) or the secondary (CKPT2) checkpoint data set.

You can specify one or more of the following options:

DSName

Displays the 1 to 44 character data set name of the checkpoint data set if it resides on DASD.

INUSE

Displays whether (YES) or not (NO) this data set is defined to a JES2 multi-access spool configuration as a checkpoint data set. For more information on this and related parameters, see z/OS JES2 Initialization and Tuning Reference, SA32-0992.

STRname

Displays the 1 to 16 character name of the structure if the primary data set resides on a coupling facility.

VOLATILE

Displays whether (YES) or not (NO) the specified checkpoint data set that resides on a coupling facility has entered the state where, if power to the coupling facility is lost, all data on the coupling facility is lost.

This parameter does not apply when a coupling facility structure becomes volatile during the checkpoint reconfiguration dialog.

VOLser

Displays the volume serial number on which the data set specified by the DSN= parameter resides.

Scope: MAS-Wide.

DUPLEX

Displays whether (ON) or not (OFF) this member of the multi-access spool configuration uses the duplexing function.

Scope: Single Member.

LOGSIZE

Displays the number of 4K storage blocks used for the change log portion of the checkpoint data set if the data set resides on DASD.

Scope: MAS-Wide.

MODE

Displays whether the multi-access spool configuration uses the data set defined by CKPT2 as the alternate primary checkpoint data set (DUAL) or as the backup to the CKPT1 data set (DUPLEX).

Scope: MAS-Wide.

NEWCKPTn

Displays an alternate data set that can replace the CKPTn data set if the CKPTn data set experiences a failure or becomes unavailable.

You can specify one or more of the following options:

DSName

Displays the 1 to 44 character name of the NEWCKPTn data set if the data set resides on DASD.

STRname

Displays the 1 to 16-character structure name of the NEWCKPTn data set if the data set resides on a coupling facility.

Note: If a checkpoint data set resides on a coupling facility structure and you attempt to display either the DSNAME= or the VOLSER= parameters, JES2 returns a null value (). When the checkpoint resides on DASD and you attempt to display STRNAME=, JES2 returns the same null value.

VOLser

The volume serial number on which the data set specified by DSName resides.

Scope: MAS-Wide.

OPVERIFY

Displays whether (Yes) or not (No) JES2 prompts the operator during a JES2-initiated I/O error checkpoint reconfiguration to verify or alter the default reconfiguration action. OPVERIFY has no meaning for a checkpoint reconfiguration entered for any other reasons.

Scope: MAS-Wide.

RECONFIG

Displays whether (Yes) or not (No) JES2 enters the checkpoint reconfiguration dialog so that you can supply the information needed to reconfigure the checkpoint data set specifications.

Scope: MAS-Wide.

VERSIONS

Displays the status of the checkpoint versioning parameter.

You can specify one or more of the following options:

MAXFAIL

Displays the greatest number of checkpoint version failures between successful updates since the last $T CKPTDEF,NUMBER= command was entered.

MAXUSED

Displays the greatest number of versions of the checkpoint data set that have been in use since the last IPL of JES2.

NUMBER

Displays the maximum number (2-50) of versions of the checkpoint data set that JES2 maintains.

NUMFAIL

Displays the number of failures since the last $T CKPTDEF,NUMBER= was entered.

STATUS

Displays whether checkpointing is active or inactive on the member.

VERSFREE

Displays the number of checkpoint versions available for updating.

WARN

Displays the percent (0-100) usage threshold of versions of the checkpoint data set.

Scope: Single Member.

VOLATILE

Displays how JES2 responds when a coupling facility enters the state where, if power to the coupling facility is lost, the data on the coupling facility is lost.

ALLCKPT

Displays the action taken if the coupling facilities on which all available checkpoint data sets reside (INUSE=YES) become volatile (unstable).

JES2 either issues a WTOR (WTOR), enters the checkpoint reconfiguration dialog (DIALOG), or ignores the change to volatile status (IGNORE).

ONECKPT

Displays the action taken if the coupling facility on which a checkpoint data set resides becomes volatile (unstable).

JES2 either issues a WTOR (WTOR), enters the checkpoint reconfiguration dialog (DIALOG), or ignores the change to volatile status (IGNORE).

Scope: Single member.

Authority Required

This command requires display authority. The description of the $T RDRnn command explains how to ensure that the authority of the appropriate MVS™ system command group is assigned.

This command requires read security access authority. For a description of assigning command input authority, see z/OS JES2 Initialization and Tuning Guide, SA32-0991.

Scope

The scope of this command varies by parameter. See the description of each parameter for its scope.

Some parameters on this command will display information about the entire MAS, while other parameters will display information about this member only.

You might want to use the parameters for this command to get information about all members of the MAS. If so, you can use the MVS ROUTE *ALL command to issue this command to all active members (if the JES2 command character is the same on all members). See z/OS MVS System Commands, SA38-0666 for more information on using the ROUTE *ALL command.

Messages

The $HASP829 message displays the current values of all the parameters on the CKPTDEF initialization statement.