Apparatus and method for extending the useful life of a data storage system
First Claim
1. Apparatus for extending the useful life of a data storage system having components subject to wear, the components subject to wear being read/write members and storage areas of a storage medium, data being read and written in the storage medium by the read/write members performing access operations on respective storage areas, the access operations imposing wear on the components subject to wear, the apparatus comprising:
- a memory in which is stored an address correction table that assigns physical addresses of the storage areas to logical addresses;
a counter that registers an access count for each of the components subject to wear;
data exchange means, operating in response to the access count for one of the components subject to wear reaching a first threshold value, for performing a data exchange operation in which data stored in a first storage area are exchanged with data stored in a second storage area,the first storage area being the one of the storage areas having the access count that reached the first threshold value and the second storage area being one of the storage areas having an access count less than the first threshold value when the components subject to wear are the storage areas,the first storage area being the one of the storage areas accessed by the one of the read/write members having the access count that reached the first threshold value and the second storage area being one of the storage areas accessed by another of the read/write members having an access count less than the first threshold value when the components subject to wear are the read/write members;
means, operating after each data exchange operation, for rewriting part of the address correction table to assign the physical addresses of the second and first storage areas after the data exchange operation to logical addresses that correspond to the physical addresses of the first and second storage areas, respectively, before the data exchange operation, andmeans, operating in response to the counter, for identifying ones of the components subject to wear having an access count less than a second threshold value, the second threshold value being less than the first threshold value;
in which,the second storage area on which the data exchange means performs the data exchange operation is one of the storage areas having the access count less than the second threshold value when the components subject to wear are the storage areas and is the one of the storage areas accessed by one of the read/write members having the access count less than the second threshold value when the components subject to wear are the read/write members.
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Accused Products
Abstract
Useful life extension for a data storage system in which either or both of read/write probes and storage areas are components subject to wear caused by the access operations. An access counter counts an access count for each component subject to wear. A data exchange module operates in response to the access count for one of the components subject to wear reaching a first threshold to perform a data exchange in which data stored in a first storage area are exchanged with data stored is a second storage area. When the components subject to wear are the storage areas, the first storage area is the storage area whose access count reached the first threshold value, and the second storage area is a storage area whose access count is less than the first threshold value. When the components subject to wear are the read/write probes, the first storage area is the storage area accessed by the read/write probe whose access count reached the first threshold value, and the second storage area is a storage area accessed by a read/write probe whose access count is less than the first threshold value. An address conversion table rewriting module operates after each data exchange to rewrite part of an address conversion table to assign the physical addresses of the storage areas after the data exchange to logical addresses that correspond to the physical addresses of the storage areas before the data exchange.
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Citations
19 Claims
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1. Apparatus for extending the useful life of a data storage system having components subject to wear, the components subject to wear being read/write members and storage areas of a storage medium, data being read and written in the storage medium by the read/write members performing access operations on respective storage areas, the access operations imposing wear on the components subject to wear, the apparatus comprising:
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a memory in which is stored an address correction table that assigns physical addresses of the storage areas to logical addresses; a counter that registers an access count for each of the components subject to wear; data exchange means, operating in response to the access count for one of the components subject to wear reaching a first threshold value, for performing a data exchange operation in which data stored in a first storage area are exchanged with data stored in a second storage area, the first storage area being the one of the storage areas having the access count that reached the first threshold value and the second storage area being one of the storage areas having an access count less than the first threshold value when the components subject to wear are the storage areas, the first storage area being the one of the storage areas accessed by the one of the read/write members having the access count that reached the first threshold value and the second storage area being one of the storage areas accessed by another of the read/write members having an access count less than the first threshold value when the components subject to wear are the read/write members; means, operating after each data exchange operation, for rewriting part of the address correction table to assign the physical addresses of the second and first storage areas after the data exchange operation to logical addresses that correspond to the physical addresses of the first and second storage areas, respectively, before the data exchange operation, and means, operating in response to the counter, for identifying ones of the components subject to wear having an access count less than a second threshold value, the second threshold value being less than the first threshold value;
in which,the second storage area on which the data exchange means performs the data exchange operation is one of the storage areas having the access count less than the second threshold value when the components subject to wear are the storage areas and is the one of the storage areas accessed by one of the read/write members having the access count less than the second threshold value when the components subject to wear are the read/write members. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for extending the useful life of a data storage system having components subject to wear, the components subject to wear being read/write members and storage areas of a storage medium, data being read and written in the storage medium by the read/write members performing access operations on respective storage areas, the access operations imposing wear on the components subject to wear, the method comprising steps of:
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providing an address correction table that assigns physical addresses of the storage areas to logical addresses; counting an access count for each of the components subject to wear; in response to the access count for one of the components subject to wear reaching a first threshold value, performing a data exchange operation in which data stored in a first storage area are exchanged with data stored in a second storage area, the first storage area being the one of the storage areas having the access count that reached the first threshold value and the second storage area being one of the storage areas having an access count less than the first threshold value when the components subject to wear are the storage areas, the first storage area being the one of the storage areas accessed by the one of the read/write members having the access count that reached the first threshold value and the second storage area being one of the storage areas accessed by another of the read/write members having an access count less than the first threshold value when the components subject to wear are the read/write members; after each data exchange operation, rewriting part of the address correction table to assign the physical addresses of the second and first storage areas after the data exchange operation to logical addresses that correspond to the physical addresses of the first and second storage areas, respectively, before the data exchange operation; and identifying ones of the components subject to wear having an access count less than a second threshold value, the second threshold value being less than the first threshold value;
in which,in the step of performing the data exchange operation, the second storage area on which the data exchange operation is performed is one of the storage areas identified in the identifying step, as having the access count less than the second threshold value when the components subject to wear are the storage areas, and is the one of the storage areas accessed by one of the read/write members identified in the identifying step as having the access count less than the second threshold value when the components subject to wear are the read/write members. - View Dependent Claims (15, 16, 17, 18, 19)
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Specification