Data storage device with small computer system interface providing persistent reservations
First Claim
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1. A disc drive, comprising:
- a spindle motor;
a disc coupled to the spindle motor for rotation therewith;
a head configured to read and write data upon the disc; and
a controller coupled to the spindle motor and the head, the controller being operatively couplable to a small computer system interface and further adapted to store persistent reservation information on the disc, the controller adapted to receive a persistent reservation command and responsively determine if the persistent reservation information is accessible and selectively provide a CHECK CONDITION response to the command based upon whether the persistent reservation information is accessible.
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Abstract
A disc drive includes a disc which is coupled to a spindle motor for rotation. A head in the disc drive is configured to read and write data upon the disc. The disc drive also includes a controller which is couplable to an SCSI interface, and adapted to store persistent reservation information on the disc.
Methods are also provided by which SCSI compliant devices can respond to persistent reservations commands in accordance with the present invention.
91 Citations
14 Claims
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1. A disc drive, comprising:
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a spindle motor;
a disc coupled to the spindle motor for rotation therewith;
a head configured to read and write data upon the disc; and
a controller coupled to the spindle motor and the head, the controller being operatively couplable to a small computer system interface and further adapted to store persistent reservation information on the disc, the controller adapted to receive a persistent reservation command and responsively determine if the persistent reservation information is accessible and selectively provide a CHECK CONDITION response to the command based upon whether the persistent reservation information is accessible. - View Dependent Claims (2, 3, 4, 5, 6)
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7. In an apparatus that is adapted to communicate over a small computer system interface, a method of executing persistent reservation commands comprising steps of:
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(a) receiving a persistent reservation out command;
(b) determining if the received command will require an update to a non-volatile memory;
(c) checking a state of non-volatile memory if the determining step (b) determines that the update is not required; and
(d) reporting an error if the checking step (c) determines that the non-volatile memory has an error. - View Dependent Claims (8, 9)
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10. In an apparatus that is adapted to communicate over a small computer system interface, a method of executing persistent reservation commands comprising steps of:
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(a) receiving a PERSISTENT RESERVE OUT command;
(b) determining whether persistent reservation information is known;
(c) if the determining step (b) determines that the persistent information is known, determining if an update to a non-volatile memory is required by the command;
(d) if the determining step (c) determines that an update is required, determining whether the non-volatile memory can be updated;
(e) if the determining step (d) determines that the non-volatile memory can be updated, then selectively determining whether an update to persistent reservation information is required; and
(f) if the determining step (e) determines that an update is not required, then terminating the command with a response indicating GOOD status. - View Dependent Claims (11, 12)
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13. In an apparatus that is adapted to communicate over a small computer system interface, a method of executing a persistent reservation out command specifying preempt and clear service action, comprising steps of:
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(a) receiving at least one command from the small computer system interface;
(b) loading the received command into a command queue;
(c) receiving a persistent reservation command after the at least one command, the persistent reservation command specifying a preempt and clear service action; and
(d) ensuring termination of the at least one command stored in the command queue based upon reception of the persistent reservation out command.
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14. A disc drive, comprising:
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a disc;
means for reading and writing data on the disc; and
control means for controlling the means for reading and writing and for tracking a state of persistent reservations related to the disc drive.
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Specification