RESTART operator command

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Note: Prior to Version 7.5 of Model 204, the command processing described below is available only to Sirius Mods customers.

The RESTART operator command requests that the Restart utility issue the equivalent of a user abend in Model 204 for the indicated user or task. This command should be used only as a last resort when a Model 204 Online is looping or hung and all efforts to clear up the situation have failed (see BUMP command). In this situation, the only options left are to cancel (FORCE under CMS) the run or to issue the RESTART utility's RESTART command. The RESTART command is preferable because:

  • The Online might intercept the abend, possibly take a snap dump, and then continue running.
  • Even if the Online does not continue, it might at least intercept the abend and terminate "cleanly," preventing files from being broken and eliminating the need to run recovery.

    Cancelling or forcing the Online ensures:

    • Any file with active updating transactions will be left broken.
    • Recovery will have to be run before the Online files can be used again.
  • The RESTART command will generally result in a CCASNAP being taken rather than (or in addition to) a SYSMDUMP, SYSUDUMP, or VMDUMP. CCASNAPs are generally easier to deal with than other types of dumps.

The "abend code" must be a 1- to 3-digit hexadecimal code that indicates the abend code to be used for the artificially generated abend. Under CMS, the abend code must be between 0C1 and 0CF. Any dumps will indicate the specified abend code.

Note: It is important to inform the support personnel that are examining the dump that the abend code was artificially generated by the RESTART utility and that the situation was actually a hung or looping Online.

To prevent accidentally terminating a user or an Online, a user number can be specified on the RESTART command. When a user number is specified on the RESTART command, no simulated abend will occur if the indicated user is not running in the Online. For example, this command simulates a 0C4 abend if user 23 is running:


If user 23 is not running, no abend is simulated.

If no user is running (a hung Online), it might be necessary to issue the RESTART command with a task number instead. Unless running MP/204, the task number must be specified as 0. If MP/204 is running, the task number must be 0 (for the maintask) or the subtask number (from 1 to NMPSUBS) to be restarted. For example, this simulates a 0A9 abend on the Model 204 maintask:


Note that it is almost always preferable to specify a user number rather than a task number on the RESTART command.

See also

  • The discussion of operator commands describes the format used on the z/OS console for the RESTART command.
  • The RESTART user 0 command is an entirely different command, which restarts Model 204 and optionally recovers files after a system failure.