Wide port emulation at serial attached SCSI expanders using virtual physical links
AssigneeAvago Technologies General IP (Singapore) Pte. Ltd.
InventorsShankar More, Mandar Joshi, Vidyadhar Pinglikar
Life of this patent
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Abstract
Methods and structure for emulating wide ports at an expander are provided. An exemplary system includes a Serial Attached Small Computer System Interface (SAS) expander. The expander includes a plurality of physical links, and a controller. The controller is able to identify a physical link coupled with a device, to generate a plurality of virtual physical links that are configured as a virtual wide port coupled with the device, and to present the virtual wide port at the expander in place of the physical link.
Claims20
A system comprising:
- a Serial Attached Small Computer System Interface (SAS) expander, comprising,
- a plurality of physical links, and
- a controller operable to identify a physical link in the plurality of physical links that is coupled with a first device, to generate a plurality of virtual physical links that are configured as a first wide port coupled with the first device, and to present the first wide port at the SAS expander in place of the physical link such that the physical link is represented as multiple physical links to a second wide port of the SAS expander, the second wide port being a subset of physical links in the plurality of physical links that allow for a second device to service multiple simultaneous connections with the first device.
A system comprising:
- a Serial Attached Small Computer System Interface (SAS) expander, comprising,
- a plurality of physical links, and
- a controller operable to identify a physical link in the physical links that is coupled with a device, to generate a plurality of virtual physical links that are configured as a virtual wide port coupled with the device, and to present the virtual wide port at the SAS expander in place of the physical link, wherein the controller comprises a wide port emulator, comprising,
- multiple store-and-forward modules that are each operable to buffer incoming data received at a virtual physical link in the plurality of virtual physical links,
- an upstream expander connection router operable to map the plurality of virtual physical links to the multiple store-and-forward modules,
- a downstream expander connection router operable to map the multiple store-and-forward modules to the physical link.
A method comprising:
- identifying a physical link of a Serial Attached Small Computer System Interface (SAS) expander, wherein the physical link is coupled with a device;
- generating a plurality of virtual physical links that are configured as a virtual wide port coupled with the device;
- presenting the virtual wide port at the SAS expander in place of the physical link;
- receiving a request to establish a connection between a wide port and the virtual wide port;
- establishing the requested connection between the wide port and the virtual wide port by programming an expander connection manager to couple physical links of the wide port with the virtual physical links of the virtual wide port;
- and
- buffering data for the virtual wide port, thereby accounting for differences in bandwidth between the virtual wide port and the physical link.
A Serial Attached Small Computer System Interface (SAS) expander, comprising:
- physical links;
- and
- a controller operable to,
- represent a physical link in the physical links as multiple virtual physical links that are coupled to one device to form a virtual wide port,
- acquire data directed to the virtual wide port,
- buffer the data directed to the virtual wide port, thereby accounting for differences in bandwidth between the virtual wide port and the physical link, and
- forward the buffered data to the physical link.
Dependencies are inferred from the claim text.