Abstract: In a computer system divided into multiple separate workload partitions, wherein at least one of the partitions contains multiple applications, and a loopback interface is made available to each partition, a method is provided for routing packets from one application to another application. In one embodiment of the invention, each packet to be routed from one application to another application in the same home partition comprises a first packet, and all other packets comprise second packets. The method comprises the steps of assigning the same pre-specified IP address to each of the first packets, and routing each of the first packets from its home partition to a loopback interface at the IP network processing layer. The method further includes marking the first packets to identify the home partition of each first packet, and directing the marked first packets to a mechanism configured to deliver each first packet only to its home partition, in response to the markings.

Abstract: A method, apparatus and computer usable program code for updating a duplicate copy of an active operating system. A set of logical volumes for an active operating system currently running on a data processing system is identified. The set of logical volumes is duplicated while the active operating system is running to form a duplicate copy of the active operating system. The duplicate copy of the active operating system is located on the same disk as the active operating system. This duplicate copy of the active operating system is updated while the active operating system is running to form an updated copy of the active operating system.