Multiple Subchannel Sets (MSS)

The Multiple Subchannel Sets (MSS) structure allows increased device connectivity for Parallel Access Volumes (PAVs). Four subchannel sets per Logical Channel Subsystem (LCSS) are designed to enable a total of 63.75K subchannels in set-0 and the addition of 64K - 1 subchannels in set-1, set-2, and set-3. MSS is supported by FICON® (CHPID type FC (both native FICON and zHPF paths) and z/OS®.