Abstract: A method and apparatus for optimizing the handling of a synchronous request issued from a system partition of a logically partitioned machine to a selected coupling facility. The coupling facility may be either an internal coupling facility residing in a separate logical partition or an external coupling facility residing on a separate physical machine; an internal coupling facility in turn runs on processors that are either dedicated to the coupling facility or shared with another logical partition. A logical partition manager maintains state information for each system partition indicating whether the partition is connected to an internal coupling facility. To ascertain the shared or non-shared status of a particular coupling facility to which it is connected, a system partition issues a Read Facility Parameters (RFP) command to the target facility, which responds with a message response block (MRB) containing a bit that is 1 if it uses dedicated processors and 0 if it uses shared processors.

Abstract: A method and apparatus for synchronizing selected logical partitions of a partitioned information handling system to a test datesource. A system operator is presented with a display panel in which the operator may specify a set of test partitions and a test clock value. Each partition designated as a test partition is synchronized to the test clock value upon being newly activated, while production partitions are synchronized to a production clock value. The first test partition to be newly activated is synchronized to the test clock value by calculating the difference between the test clock value and a host clock value and storing the difference as an epoch offset for that partition. Each subsequently activated test partition is synchronized to the test clock value by copying the epoch offset of the previously activated test partition.

Abstract: A server function is provided in a hardware machine which is divided into a plurality of logical partitions, each of which functions as a virtual hardware machine. The hardware machine has a non-user-accessible storage device for storing machine control code and other non-user-accessible code and, optionally, a user-accessible storage device for storing applications and other user-accessible code. Defined partition types include server mode partitions that are inaccessible to a user and non-server mode partitions that are accessible to a user. The hardware machine is divided into one or more logical partitions including at least one server mode partitions and, optionally, one or more non-server mode partitions. Server code for providing the server function is stored on the non-user-accessible storage device and is loaded into the server mode partition from the non-user-accessible storage device in response to an activation signal to enable the server mode partition.

Abstract: A request is made by a system in a first logical partition, within a logically partitioned data processing system, to dynamically change the I/O configuration of the host system in a way that affects a system in a second logical partition. The hypervisor intercepts the request, ensures the serialization of such dynamic I/O requests, and allows dynamic reconfiguration to proceed. Subsequently, the hypervisor determines the effect of the reconfiguration on the second partition, and notifies the second partition of the change.