Abstract: Methods and structure are provided for “spoofing” an active connection between a Serial Attached SCSI (SAS) initiator and a SAS target. The structure includes a SAS expander, comprising multiple physical links with associated transceivers (PHYs), switching hardware, a memory, and a control unit. Each PHY is operable to receive incoming Open Address Frames (OAFs) from SAS initiators that request connections with target devices. The switching hardware is operable to selectively link PHYs of the expander with each other to enable connections between initiators and target devices. The control unit is operable to determine that a connection requested by a received OAF cannot be completed, is operable to transmit an OPEN ACCEPT to the SAS initiator that transmitted the OAF responsive to making the determination, and is operable to store I/O received from the SAS initiator for the requested connection in the memory, responsive to transmitting the OPEN ACCEPT.

Abstract: Methods, systems, and processor-readable media are disclosed for detecting multiple expanders in a SAS topology having the same address. A root expander can be connected to a plurality of expanders, wherein one or more expanders among the plurality of expanders possesses a same SAS address as the root expander. The same SAS address can be identified and stored in a route table against a physical layer identifier through which the expander(s) communicate with the root expander in order to assist in identifying duplicate expanders in the SAS topology.

Abstract: Methods, systems and processor-readable media are disclosed for implementing a “smart” discovery process in a data transfer regime having one or more expanders and one or more initiators. Data traffic associated with such a discovery process can be reduced and one or more of the initiators can be prevented from blocking input/output to particular components in communication with the data transfer regime, thereby improving and completing the discovery process in an optimal time frame while enhancing the performance of the initiator(s).

Abstract: A SAS expander includes DMD timers for each PHY so that the expander can track disconnected devices directly connected to the expander and signal a SAS controller when the DMD is exceeded. A system including such SAS expanders may reduce the load on the system controller. A controller may recognize expanders capable of tracking DMDs for backwards compatibility.

Abstract: Methods, systems and processor-readable media are disclosed for implementing a “smart” discovery process in a data transfer regime having one or more expanders and one or more initiators. Data traffic associated with such a discovery process can be reduced and one or more of the initiators can be prevented from blocking input/output to particular components in communication with the data transfer regime, thereby improving and completing the discovery process in an optimal time frame while enhancing the performance of the initiator(s).

Abstract: Methods and structure are provided for “spoofing” an active connection between a Serial Attached SCSI (SAS) initiator and a SAS target. The structure includes a SAS expander, comprising multiple physical links with associated transceivers (PHYs), switching hardware, a memory, and a control unit. Each PHY is operable to receive incoming Open Address Frames (OAFs) from SAS initiators that request connections with target devices. The switching hardware is operable to selectively link PHYs of the expander with each other to enable connections between initiators and target devices. The control unit is operable to determine that a connection requested by a received OAF cannot be completed, is operable to transmit an OPEN ACCEPT to the SAS initiator that transmitted the OAF responsive to making the determination, and is operable to store I/O received from the SAS initiator for the requested connection in the memory, responsive to transmitting the OPEN ACCEPT.

Abstract: Methods, systems, and processor-readable media are disclosed for detecting multiple expanders in a SAS topology having the same address. A root expander can be connected to a plurality of expanders, wherein one or more expanders among the plurality of expanders possesses a same SAS address as the root expander. The same SAS address can be identified and stored address in a route table against a physical layer identifier through which the expander(s) communicate with the root expander in order to assist in identifying duplicate expanders in the SAS topology.

Abstract: A SAS expander includes DMD timers for each PHY so that the expander can track disconnected devices directly connected to the expander and signal a SAS controller when the DMD is exceeded. A system including such SAS expanders may reduce the load on the system controller. A controller may recognize expanders capable of tracking DMDs for backwards compatibility.