Automating a Shutdown

z/VM® allows you to shut down guests automatically, by sending them a shutdown signal and giving them time to respond to that signal. A signal can be sent in response to a hardware event, such as a deactivation of the z/VM image, or as a result of a SHUTDOWN, FORCE, or SIGNAL command.

The amount of time a guest has to shut down can be defined using the SET system configuration statement. This statement can also be used to specify how much time should be reserved to allow z/VM itself to shut down.

Only some guest operating systems have programming support to enable them to receive and react to shutdown signals. For example, z/VM itself has this support. In addition:
  • A guest that is enabled for shutdown signals can issue the SET SHUTSIGNAL command to temporarily disable from receiving shutdown signals and later to re-enable for shutdown signals.
  • The QUERY SIGNAL command can be used to determine whether a guest is currently enabled to receive shutdown signals.
  • The QUERY SHUTDOWN STATUS command can be used:
    • By a guest, to determine whether the entire system is being shut down or whether the guest was the only user signaled to shut down.
    • To tailor how the guest enabled for signals shuts down in an orderly manner.
For more information about automatic guest shutdown, refer to the following: