Abstract: Methods and structure are provided for Serial Attached SCSI (SAS) expanders that program their own routing attributes. The structure includes a SAS expander comprising multiple physical links with associated transceivers (PHYs), wherein the PHYs are configured into ports at the expander, and a memory that defines routing attributes for each of the ports. The SAS expander also comprises a control unit that is operable to detect a discovery Serial Management Protocol (SMP) request received at a port of the expander, and that is further operable to set the routing attribute for the port to subtractive routing responsive to detecting the SMP request.

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: An expander for a device architecture, such as a SAS-compatible expander for a SAS architecture, is configured to follow a set of discovery rules that are applied following detection of a discovery-triggering event, such as system power up or reset. According to one of the discovery rules, the expander waits until after a specified duration following the detected discovery-triggering event before passing on, to any other expanders, any requests to check the status of their discovery processing. Using appropriate values for the specified durations for different expanders, the discovery procedure will be performed without any infinite-messaging problems, even when the device architecture has a loop.

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, 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: An expander for a device architecture, such as a SAS-compatible expander for a SAS architecture, is configured to follow a set of discovery rules that are applied following detection of a discovery-triggering event, such as system power up or reset. According to one of the discovery rules, the expander waits until after a specified duration following the detected discovery-triggering event before passing on, to any other expanders, any requests to check the status of their discovery processing. Using appropriate values for the specified durations for different expanders, the discovery procedure will be performed without any infinite-messaging problems, even when the device architecture has a loop.

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: Methods and structure are provided for Serial Attached SCSI (SAS) expanders that program their own routing attributes. The structure includes a SAS expander comprising multiple physical links with associated transceivers (PHYs), wherein the PHYs are configured into ports at the expander, and a memory that defines routing attributes for each of the ports. The SAS expander also comprises a control unit that is operable to detect a discovery Serial Management Protocol (SMP) request received at a port of the expander, and that is further operable to set the routing attribute for the port to subtractive routing responsive to detecting the SMP request.