Restarting programs
The system restart routine retrieves the information recorded in a checkpoint record, restores the contents of main storage and all registers, and restarts the program.
About this task
You can begin the restart routine in one of two ways:
- Automatically at the time an interruption stopped the program
- At a later time as a deferred restart
The RD parameter
of the job control language determines the type of restart. You can
use the RD parameter on either the JOB or
the EXEC statement. If coded on the JOB statement,
the parameter overrides any RD parameters on the EXEC statement.
To
suppress both restart and writing checkpoints, code RD=NC.
SORT or MERGE operation,
an error message is issued and the restart is canceled. Only checkpoints
taken by DFSORT are valid.Data sets that have the SYSOUT parameter coded
in their DD statements are handled in various ways
depending on the type of restart.
If the checkpoint data set
is multivolume, include in the VOLUME parameter the
sequence number of the volume on which the checkpoint entry was written.
If the checkpoint data set is on a 7-track tape with nonstandard labels
or no labels, the SYSCHK DD statement must contain DCB=(TRTCH=C,.
. .).