SYSCKEOV DD statement - IBM-JCL

Purpose
Use the SYSCKEOV DD statement to define a checkpoint data set for checkpoint records from the checkpoint at end-of-volume (EOV) facility. The checkpoint at EOV facility is invoked by a DD CHKPT parameter.

1.Syntax

//SYSCKEOV DD parameter[,parameter]... [comments]

2.Parameters on SYSCKEOV DD Statements

When Creating a Checkpoint Data Set

  • Code a SPACE parameter, but do not request secondary space. The primary space request must be large enough to hold all checkpoints; if not, the job abnormally terminates.
  • Do not code the RLSE subparameter of the SPACE parameter.
  • Code the CONTIG subparameter of the SPACE parameter to request contiguous space. The system otherwise provides additional primary space using extents.
  • The SYSCKEOV DD statement must define a BSAM data set, but cannot define a partitioned data set extended (PDSE).
  • Code DISP=MOD to reduce loss of checkpoint data in case of a system failure during checkpointing.

Other Parameters

  • Do not code on the SYSCKEOV DD statement the following:
  • – CHKPT=EOV parameter.
    – DCB parameter. All DCB information is provided by the checkpoint at EOV facility.
    – DEFER subparameter of the UNIT parameter.
  • If you code the LABEL parameter, you must specify LABEL=(,SL) for IBM standard labels.
  • If the SYSCKEOV data set resides on a direct access storage device, that device cannot be shared with another processor.

3.Location in the JCL
If you code a CHKPT parameter on any DD statements in a job step, place a SYSCKEOV DD statement in the DD statements for the step.

4.Example of the SYSCKEOV DD Statement

//SYSCKEOV DD DSNAME=CKPTDS,UNIT=TAPE,DISP=MOD

This statement defines a checkpoint data set for checkpoint at EOV records.

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