1. A computer-implemented method of managing migration of a logical partition between shared memory partition data processing systems, the method comprising: managing migration of a logical partition from a source, shared memory partition data processing system (source system) to a target, shared memory partition data processing system (target system), the managing comprising: transferring a portion of logical partition state information for the migrating logical partition from the source system to the target system by copying at the source system contents of a logical page of the migrating logical partition into a state record buffer for forwarding to the target system; forwarding the state record buffer to the target system; and determining whether the migrating logical partition is suspended at the source system, and if not, copying at the target system contents of the state record buffer to paging storage of the target system, the paging storage being external to physical memory managed by a hypervisor of the target system.