Patent ID: 9342413
Filing Date: 2016-05-17
CPC Classification: G06F

Claim Text:
1. A redundant array of independent disk (RAID) head whose device-side I/O device interconnect is a serial-attached small computer system interface (Serial-Attached SCSI) (hereinafter SAS RAID head), the SAS RAID head being disposed between at least one initiator and at least one storage device, the SAS RAID head comprising: an enclosure; a plurality of I/O device interconnect ports disposed on an exterior of the enclosure; a first external storage virtualization controller (external SVC) disposed inside the enclosure, wherein one or more of the plurality of I/O device interconnect ports couple the first external SVC to the at least one initiator for executing at least one I/O operation in response to at least one I/O request sent out from the at least one initiator, wherein at least one of the plurality of I/O device interconnect ports is configurable in either a target mode or an initial mode and is selectively set in either the target mode or the initial mode, wherein with regards to data read and/or data write commands, the target mode configures the I/O device interconnect port to only process the data read and/or data write commands passively received from the at least one initiator as a host-side I/O device interconnect port disposed on a path of a host-side I/O device interconnect for electrically coupling the first external SVC to the at least one initiator, and the initial mode configures the I/O device interconnect port to actively issue the data read and/or data write commands to connected devices as a device-side I/O device interconnect port disposed on a path of a device-side I/O device interconnect for electrically coupling the first external SVC to the storage device; an expander circuitry, directly connected to the first external SVC and a second external SVC as well as directly connected to the at least one storage device, is divided into a plurality of zones, the plurality of zones including a first zone connected to at least one first initiator, a second zone connected to at least one second initiator, and a third zone connected to the at least one storage device; and a power supply unit coupled to the first external SVC for providing electrical power; wherein the device-side I/O device interconnect of the first external SVC is a Serial-Attached SCSI (SAS) device-side I/O device interconnect; and wherein the enclosure has no internal space to accommodate a physical storage device (PSD) for storing pay-load data and the PSD is externally connected to the enclosure via one of the plurality of I/O device interconnect ports disposed on the exterior thereof.