Storage system, storage control device, and storage control method
First Claim
1. A storage system, comprising:
- at least one disk device; and
a control unit which performs reading and writing of data from and to said disk device according to requests from a higher-level apparatus, wherein said control unit comprises;
a cache memory which stores data of said disk device; and
a processing unit which read-accesses said disk device and receives read data and a response result from said disk device, and wherein said processing unit, when said response upon receiving said read data is a recovered read error response, performs retry read access of the same data on said disk device, discriminates whether the response from said disk device accessed by said retry read does not include an error, and judges the read data obtained from said retry read access to be valid.
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Accused Products
Abstract
In a storage system, a disk device performs recovery and transfers read data to a control device, and the control device judges the validity of the recovery to prevent a transfer of erroneous data. A control device read-accesses a disk device, and the disk device returns read data and a recovered read error response. A control device, at the time of an initial recovered read error, performs a retry of a similar command, and if an error does not occur for read commands including the retry read command, judges the data to be valid. Uncertain data (suspect data) upon occurrence of a recovered read error is restored through disk retry, and accurate read data can be transferred to the host.
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Citations
33 Claims
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1. A storage system, comprising:
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at least one disk device; and
a control unit which performs reading and writing of data from and to said disk device according to requests from a higher-level apparatus, wherein said control unit comprises;
a cache memory which stores data of said disk device; and
a processing unit which read-accesses said disk device and receives read data and a response result from said disk device, and wherein said processing unit, when said response upon receiving said read data is a recovered read error response, performs retry read access of the same data on said disk device, discriminates whether the response from said disk device accessed by said retry read does not include an error, and judges the read data obtained from said retry read access to be valid. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A storage control device, which in response to a request from a higher-level apparatus performs reading and writing of data from and to at least one disk device, comprising:
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a cache memory which stores data of said disk device; and
a processing unit which read-accesses said disk device, and receives read data and a response result from said disk device, wherein said processing unit, when said response upon receiving said read data is a recovered read error response, performs retry read access of the same data on said disk device, discriminates that the response from said disk device to said retry read access does not comprise an error, and judges the read data obtained by said retry read access to be valid. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A storage control method for performing reading and writing of data from and to at least one disk device, in response to a request from a higher-level apparatus, comprising the steps of:
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read-accessing said disk device, and receiving read data and a response result from said disk device;
performing retry read access of the same data on said disk device when said response upon reception of said read data is a recovered read error response; and
discriminating that the response from said disk device to said retry read access does not comprise an error, and judging the read data obtained by said retry read access to be valid. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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Specification