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: Systems and methods presented herein provide for recovering a failed expander in a data storage switch to restore the switch to optimal. In one embodiment, a data storage switch includes a master expander having a first firmware module operable to link a plurality of logical volumes to at least one initiator through a first plurality of physical transceivers. The data storage switch also includes a slave expander having a second firmware module operable to link the plurality of logical volumes to the at least one initiator through a second plurality of physical transceivers. The slave expander is operable to detect a firmware failure of the master expander to link at least a portion of the logical volumes to the at least one initiator, to load a copy of second firmware module into the master expander, and to initiate the master expander to link to the logical volumes to the at least one initiator through the first plurality of physical transceivers based on the copy of the second firmware module.

Abstract: Systems and methods presented herein provide for recovering a failed expander in a data storage switch to restore the switch to optimal. In one embodiment, a data storage switch includes a master expander having a first firmware module operable to link a plurality of logical volumes to at least one initiator through a first plurality of physical transceivers. The data storage switch also includes a slave expander having a second firmware module operable to link the plurality of logical volumes to the at least one initiator through a second plurality of physical transceivers. The slave expander is operable to detect a firmware failure of the master expander to link at least a portion of the logical volumes to the at least one initiator, to load a copy of second firmware module into the master expander, and to initiate the master expander to link to the logical volumes to the at least one initiator through the first plurality of physical transceivers based on the copy of the second firmware module.

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.