Patent ID: 7761610
Filing Date: 2010-07-20
Classification: G06F

Abstract:
1. A method for defining and accessing a peer-to-peer remote copy secondary device within a subchannel set other than subchannel set zero while maintaining transparency to application I/O requests, the method comprising: identifying a peer-to-peer remote copy (PPRC) pairing, the PPRC pairing comprising a PPRC primary device definition corresponding to a PPRC primary device and a PPRC secondary device definition corresponding to a PPRC secondary device that is associated with the primary device definition, the PPRC pairing being assigned to a subchannel set zero; designating within an operating system that a PPRC secondary device definition can be assigned to a predetermined Subchannel set other than subchannel set zero; associating the PPRC secondary device with the predetermined subchannel set; associating I/O that is associated with the PPRC secondary device with a parameter value, wherein the parameter value serves as an indicator of the subchannel set with which the PPRC secondary device is associated; defining the PPRC secondary device as a special device indicating that the PPRC secondary device resides in the predetermined subchannel set; associating the PPRC secondary device with a duplicate device address of the PPRC primary device, the duplicate device address residing in the predetermined subchannel set; pointing to the duplicate device address by a unit control block (UCB) lookup table (ULUT); and executing an I/O request at the PPRC secondary device utilizing the predetermined subchannel set.