Notes on the DCB for a Checkpoint Data Set

The following restrictions apply to the DCB for a checkpoint data set:

The checkpoint routine writes all checkpoint records in both 400- and 4096-byte blocks.
Requests for two channel programs or chained scheduling apply to the writing of all checkpoint records. Such requests do not apply to the reading of checkpoint records for a restart.
OPTCD=Q cannot be specified in the DCB, because checkpoints are not character data.
Following errors that leave the DCB invalid (for example, a D37 abend), the DCB must be closed and opened again, if additional checkpoints will be taken using this DCB.
Do not code the DCBE parameter on the DCB macro.