You can invoke a checkpoint for a task by entering the <mix number> BR + form of the BR command. If the checkpoint is accepted, it is executed with DISK as the device option and PURGE as the disposition option. Checkpoint files are therefore created on DISK family with a checkpoint number of 0.

If the BRCLASS task attribute value is ONCEONLY, the task is discontinued after the checkpoint.

The system might delay execution of the checkpoint request if it is not immediately able to save the task stack correctly. For example, a checkpoint request cannot be completed while the task is waiting on an event. If the checkpoint request is being delayed, a BR command shows a checkpoint status of REQUESTED.