Abstract: A method, apparatus, and computer implemented instructions for controlling power in a data processing system having a plurality of logical partitions. Responsive to receiving a request to turn off the power for a logical partition within the plurality of logical partitions in the data processing system, a determination is made as to whether an additional partition within the plurality of logical partitions is present in the data processing system. The power is turned off in the data processing system in response to a determination an additional partition within the plurality of logical partitions is absent in the data processing system. The logical partition is shut down in response to a determination that an additional partition within the plurality of logical partitions is present in the data processing system. The mechanism of the present invention also provides for rebooting logical partitions. A request is received to reboot a logical partition within the plurality of logical partitions.

Abstract: In a computer system, upon the occurrence of a reboot command, RunTime Abstraction Services (RTAS) microcode is loaded onto a first host processor. The service processor, upon request from the RTAS microcode, then issues a command to reset all host processors other than the first host processor on which the RTAS microcode resides, and then the RTAS microcode issues a series of commands to reset all I/O adapters. Once the host processors and I/O adapters have been reset, they are initialized to a predetermined, known state. Only after the host processors and I/O adapters have been reset and initialized is the reboot request executed. By resetting all but the first host processor and the I/O adapters before executing the reboot request, all activity originating from the host processors and from the I/O drawers is terminated, so that when the reboot request is executed, the host processors and I/O drawers are ready for initialization.

Abstract: A method, apparatus, and computer implemented instructions for controlling power in a data processing system having a plurality of logical partitions. Responsive to receiving a request to turn off the power for a logical partition within the plurality of logical partitions in the data processing system, a determination is made as to whether an additional partition within the plurality of logical partitions is present in the data processing system. The power is turned off in the data processing system in response to a determination an additional partition within the plurality of logical partitions is absent in the data processing system. The logical partition is shut down in response to a determination that an additional partition within the plurality of logical partitions is present in the data processing system. The mechanism of the present invention also provides for rebooting logical partitions. A request is received to reboot a logical partition within the plurality of logical partitions.