Checkpoint File (CKPT)
The Checkpoint file is a VSAM KSDS that contains checkpoint information generated by the DTF during execution of a copy operation. The Checkpoint file consists of variable length records, one per Process that has checkpointing specified. The average record length is 256 bytes. The equivalent of one cylinder of space is allocated during the installation. The size of the Checkpoint file can be influenced by the number of days you retain checkpoint information according to the initialization parameter, CKPT.DAYS.