I/O errors

The checkpoint routine issues return code 0C if it encounters a permanent I/O error when:

Completing an outstanding VSAM I/O request
Quiescing queued access method I/O operations
- An exception occurs when QSAM is used and the skip or accept option is specified in the EROPT operand of the data set's data control block. In this case, code 00 is returned.
Writing the checkpoint data set.

When an access method other than QSAM is used, your program can ensure that input/output operations are complete before it executes the CHKPT macro instruction; it can thereby avoid having read or written an erroneous record while quiescing.

If a permanent error occurs when the system reads a checkpoint data set to perform a restart, the restart step is terminated abnormally with the system completion code 13F. Further restart of the step is not attempted.