The IXLCACHE request types that allow you to specify buffer storage areas generally result in data being transferred directly between the data buffer storage and the coupling facility storage. The coupling facility transfers data using real storage addresses; therefore, the data buffer storage must be fixed in a specific, known real storage location and remain so until the coupling facility has transferred all data for the request.

The data buffers for an IXLCACHE request can be addressable in the caller's primary, secondary, or home address space, from the PASN access list, or from the DU access list. The system assigns ownership of a data buffer to the address space either in which the buffer storage resides or that has an associated data space in which the buffer storage resides.