Patent ID: 7660919

Claim:
A program storage device readable by a machine, tangibly embodying a program of instructions executable by a machine to perform operation for assigning I/O priority by one of a plurality of initiator devices in an open system, an initiator device in an open system being a host system which uses command descriptor blocks to access fixed block devices on logical units, said operations comprising: receiving at a device driver of said one of said plurality of initiator devices, a datapath command for setting a default I/O priority for a specified logical unit, said default I/O priority value being specific to an application at said one of said plurality of initiator devices; parsing said datapath command to determine said default I/O priority value; storing said default I/O priority value for said logical unit to a priority store of a storage controller on said logical unit; exiting said datapath command; and operating said storage controller to access said priority store and process I/O requests from said one of said plurality of initiator devices in accordance with said default I/O priority value.