REDUCING WRITE I/O LATENCY USING ASYNCHRONOUS FIBRE CHANNEL EXCHANGE
First Claim
1. A Fibre Channel (FC) Protocol for SCSI (FCP) target, comprising:
- a FC port; and
a processor, adapted to communicate with a FCP initiator via the FC port;
wherein the FCP target is configured to send one or more FC write control information units (IUs) to the FCP initiator within a first FC exchange to request a transfer of data associated with a FCP write command IU previously sent to the FCP target by the FCP initiator within a second FC exchange;
wherein the first FC exchange is distinct from the second FC exchange;
wherein a payload of each of the one or more write control IUs comprises;
an originator exchange identifier (OX_ID) value with which the FCP initiator originated the second exchange; and
a responder exchange identifier (RX_ID) value assigned by the FCP target for the second exchange.
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Accused Products
Abstract
A FCP initiator sends a FCP write command to a FCP target within a second FC Exchange, and the target sends one or more FC write control IUs to the initiator within a first FC Exchange to request a transfer of data associated with the write command. The first and second FC exchanges are distinct from one another. A payload of each write control IU includes an OX_ID value with which the initiator originated the second Exchange and a RX_ID value assigned by the FCP target for the second exchange. The two Exchanges yield a full-duplex communication environment between the initiator and target that enables the reduction or elimination of latencies incurred in a conventional FCP write I/O operation due to the half-duplex nature of a single FC Exchange. The write control IU may be an enhanced FCP_XFER_RDY IU or a new FC IU previously undefined by the FCP standard.
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Citations
20 Claims
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1. A Fibre Channel (FC) Protocol for SCSI (FCP) target, comprising:
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a FC port; and a processor, adapted to communicate with a FCP initiator via the FC port; wherein the FCP target is configured to send one or more FC write control information units (IUs) to the FCP initiator within a first FC exchange to request a transfer of data associated with a FCP write command IU previously sent to the FCP target by the FCP initiator within a second FC exchange; wherein the first FC exchange is distinct from the second FC exchange; wherein a payload of each of the one or more write control IUs comprises; an originator exchange identifier (OX_ID) value with which the FCP initiator originated the second exchange; and a responder exchange identifier (RX_ID) value assigned by the FCP target for the second exchange. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A Fibre Channel (FC) Protocol for SCSI (FCP) initiator, comprising:
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a FC port; and a processor, adapted to communicate with a FCP target via the FC port; wherein the FCP initiator is configured to receive one or more FC write control information units (IUs) from the FCP target within a first FC exchange requesting a transfer of data associated with a FCP write command IU previously sent to the FCP target by the FCP initiator within a second FC exchange; wherein the first FC exchange is distinct from the second FC exchange; wherein a payload of each of the one or more write control IUs comprises; an originator exchange identifier (OX_ID) value with which the FCP initiator originated the second exchange; and a responder exchange identifier (RX_ID) value assigned by the FCP target for the second exchange. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A method, comprising:
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sending, by a Fibre Channel (FC) Protocol for SCSI (FCP) target, one or more FC write control information units (IUs) to an FCP initiator within a first FC exchange to request a transfer of data associated with a FCP write command IU previously sent to the FCP target by the FCP initiator within a second FC exchange; wherein the first FC exchange is distinct from the second FC exchange; wherein a payload of each of the one or more write control IUs comprises; an originator exchange identifier (OX_ID) value with which the FCP initiator originated the second exchange; and a responder exchange identifier (RX_ID) value assigned by the FCP target for the second exchange. - View Dependent Claims (17, 18, 19, 20)
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Specification