With z/VM 4.3 the service processor signal that tells the operating system the LPAR is about to power down has been virtualized. Using the SERVC instruction (the relevant parameter lists etc. have been opened to the public) you can register that you interested in receiving such a signal. Thus when:
1. Real LPAR is about to power down 2. z/VM is going to shutdown 3. The #CP SIGNAL SHUTDOWN command is issued You will receive an external interruption (0x2401). You use the SERVC instruction to fetch the event data being passed (which consists of a value representing the number of seconds/minutes/hours that will elapse before the shutdown/power off will take effect). After fielding said interrupt Linux can invoke the ctrl-alt-del() function to initiate an orderly shutdown. So if you have a farm of virtual servers who have registered to receive this indication, they can shutdown automatically without the use of PROP/secondary users/whatever. > -----Original Message----- > What does this patch do? Thanks. > > Peter
