Abstract: A method and controller for implementing device physical location identification in a Serial Attached SCSI (SAS) fabric using resource path groups, and a design structure on which the subject controller circuit resides are provided. The device physical location identification includes a Resource Path Group (RPG). Each RPG provides a unique persistent physical locator of a storage device in the system. Each RPG including at least two Resource Paths (RPs) and each RP has a fixed size identifying a type and a series of egress ports. A persistent RPG is stored within the device metadata on the storage device.

Abstract: A method and controller for implementing device physical location identification in a Serial Attached SCSI (SAS) fabric using resource path groups, and a design structure on which the subject controller circuit resides are provided. The device physical location identification includes a Resource Path Group (RPG). Each RPG provides a unique persistent physical locator of a storage device in the system. Each RPG including at least two Resource Paths (RPs) and each RP has a fixed size identifying a type and a series of egress ports. A persistent RPG is stored within the device metadata on the storage device.

Abstract: A redundancy manager preferably in an I/O adapter has been disclosed to manage commands to peripheral devices in a computer system. These peripheral devices have multiple ports and may have a different bus associated with each port. The buses, referred to as independent pathways, moreover, need not have the same protocol. The redundancy manager determines the number of independent pathways connected to the peripheral device, presents only one logical device to the operating system and any device driver and any other command or device processing logic in the command path before the redundancy manager. For each incoming command, the redundancy manager determines which pathways are properly functioning and selects the best pathway for the command based on load balancing considerations and any ordering semantics that must be preserved in the incoming command and any outstanding commands and associated data that have not yet executed.

Abstract: A redundancy manager preferably in an I/O adapter has been disclosed to manage commands to peripheral devices in a computer system. These peripheral devices have multiple ports and may have a different bus associated with each port. The buses, referred to as independent pathways, moreover, need not have the same protocol. The redundancy manager determines the number of independent pathways connected to the peripheral device, presents only one logical device to the operating system and any device driver and any other command or device processing logic in the command path before the redundancy manager. For each incoming command, the redundancy manager determines which pathways are properly functioning and selects the best pathway for the command based on load balancing considerations and any ordering semantics that must be preserved in the incoming command and any outstanding commands and associated data that have not yet executed.