Recovery by CPU restart

The operator can initiate recovery from some system incidents, such as loops and uncoded wait states, by issuing a restart to the processor that has the problem. The restart reason that is entered as part of the restart process directs the system to perform one of two recovery actions:
Restart reason 0
The system tries to display message IEA500A on the first two consoles defined as master or alternate and locally attached to the system issuing the message. The message identifies the current unit of work on the target processor. The operator can reply either:
  • RESUME to allow the current unit of work to continue
  • ABEND to end that unit of work with an abend X'071'

If the operating system cannot communicate with the either console to issue message IEA500A, it ends the current unit of work with an abend X'071'.

Restart reason 1
The operating system:
  • Interrupts the current unit of work on the target processor
  • Detects and attempts to repair errors in critical system areas
  • Writes a logrec data set error record for completion code X'071' with reason code 4 when repair actions were taken
  • Reports the results of some of the actions taken in message IEA501I
  • Returns control to the interrupted unit of work
Note: Restart of the CPU in a restartable wait state ignores the restart reason.

See MVS system commands reference for information about restart.