Patent US5210865A successfully refreshed from Google Patents.
US5210865A
Expired / Lapsed
US
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Transferring data between storage media while maintaining host processor access for I/O operations
Assignee: Hewlett Packard Development Co LP
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Filing: 1992-08-04
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Granted: 1993-05-11
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Expires: 2012-08-04
Abstract
Abstract A system and method for transferring data from a first storage medium to a second storage medium, each of the storage media being divided into corresponding data blocks, the method comprising steps of: (a) reading data stored in a first data block in the first storage medium, the first data block initially constituting a current data block; (b) comparing data read in the current data block to data stored in a corresponding data block in the second storage medium; (c) if the data compared in step b are identical, reading data stored in a different data block in the first storage medium, the different data block becoming the current data block, and returning to step b; (d) modifying the data stored in one of the storage media such that the data in the current data block is identical to the corresponding data in the second storage medium; and (e) rereading the data in the current data block and returning to step b.
Inventors
- 👤 Scott H. Davis
- 👤 William L. Goleman
- 👤 David W. Thiel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:06
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/16; G06F11/20; G06F11/2053; G06F11/2056; G06F11/2082; G06F11/2087
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
247 words
A method of transferring data between a first storage medium and a second storage medium, at least said first storage medium being accessible to one or more host processors for I/O operations that include writing data to said first storage medium, each of said storage media including data blocks with at least some data blocks of said first storage medium having corresponding data blocks in said second storage medium, said method comprising the steps of: (a) reading data stored in a first data block in said first storage medium, the first data block initially constituting a current data block; (b) comparing the data read in said current data block to data stored in a corresponding data block in said second storage medium; (c) if the data compared in step b are identical, reading data stored in another data block in said first storage medium, said another data block becoming the current data block, and returning to step b; (d) if the data compared in step b are not identical, modifying the data stored in one of said storage media by transferring data between said storage media to cause the data in said current data block and the data in said corresponding data block in said second storage medium to be identical while maintaining access to said first storage medium for said I/O operations by said one or more of said host processors; and (e) rereading the data in said current data block and returning to step b.
Claim 2
Independent Claim
247 words
A method of transferring data between a first storage medium and a second storage medium, at least said first storage medium being accessible to one or more host processors for I/O operations that include writing data to said first storage medium, each of said storage media including data blocks with at least some data blocks of said first storage medium having corresponding data blocks in said second storage medium, said method comprising the steps of: (a) reading data stored in a first data block in said first storage medium, the first data block initially constituting a current data block; (b) comparing the data read in said current data block to data stored in a corresponding data block in said second storage medium; (c) if the data compared in step b are identical, reading data stored in another data block in said first storage medium, said another data block becoming the current data block, and returning to step b; (d) if the data compared in step b are not identical, modifying the data stored in one of said storage media by transferring data between said storage media to cause the data in said current data block and the data in said corresponding data block in said second storage medium to be identical while maintaining access to said first storage medium for said I/O operations by said one or more of said host processors; and (e) rereading the data in said current data block and returning to step b.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said step of modifying comprises modifying the data in said second storage medium.
Claim 4
Dependent Claim
35 words
The method of claim 2 wherein said step of modifying comprises writing said data read from the current data block in said first storage medium to the corresponding data block in said second storage medium.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein said different data block is a data block adjacent to said current data block.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein each data block in said first storage medium is compared to a corresponding data block in said second storage medium.
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein each of said storage media are members of a shadow set of storage media.
Claim 8
Dependent Claim
19 words
The method of claim 6 wherein each of said storage media may be directly accessed by a host processor.
Claim 9
Dependent Claim
23 words
The method of claim 6 wherein each of said storage media may be directly accessed by each of a plurality of host processors.
Claim 10
Dependent Claim
13 words
The method of claim 1 wherein said storage media are disk storage devices.
Claim 11
Independent Claim
221 words
A method of managing a shadow set of storage media that are accessible by one or more host processors for I/O operations that include writing data thereto, each one of said storage media having storage locations at least some of which correspond to storage locations of another one of said storage media, the method comprising the steps of: A. carrying out successive comparisons of data stored in said corresponding locations of said plurality of said storage media, respectively; and B. performing a management operation on at least one of said storage media, said management operation comprising, for each of said corresponding locations where said comparisons indicated that the data in said corresponding locations were not identical; a. reading data from locations in a first one of said storage media and writing said data to said corresponding locations a second one of said storage media while maintaining access to at least said first storage medium for said I/O operations by said one or more of said host processors; b. comparing the data in said corresponding locations after said writing to determine if the data in said corresponding locations are identical; and c. repeating step a if the comparison of step b indicates that the data in said corresponding locations are not identical, otherwise terminating said management operation as to said storage locations.
Claim 12
Independent Claim
221 words
A method of managing a shadow set of storage media that are accessible by one or more host processors for I/O operations that include writing data thereto, each one of said storage media having storage locations at least some of which correspond to storage locations of another one of said storage media, the method comprising the steps of: A. carrying out successive comparisons of data stored in said corresponding locations of said plurality of said storage media, respectively; and B. performing a management operation on at least one of said storage media, said management operation comprising, for each of said corresponding locations where said comparisons indicated that the data in said corresponding locations were not identical; a. reading data from locations in a first one of said storage media and writing said data to said corresponding locations a second one of said storage media while maintaining access to at least said first storage medium for said I/O operations by said one or more of said host processors; b. comparing the data in said corresponding locations after said writing to determine if the data in said corresponding locations are identical; and c. repeating step a if the comparison of step b indicates that the data in said corresponding locations are not identical, otherwise terminating said management operation as to said storage locations.
Claim 13
Independent Claim
221 words
An apparatus for managing a shadow set of storage media accessible by one or more host processors for I/O operations that include writing data thereto, each one of said storage media having storage locations at least some of which correspond to storage locations of another one of said storage media, comprising: means for carrying out successive comparisons of data stored in said corresponding locations of said plurality of said storage media, respectively; and means, responsive to said comparisons, for performing a management operation on at least one of said storage media, said management operation comprising, for each of said corresponding locations where said comparisons indicated that the data in said corresponding locations were not identical; a. reading data from locations in a first one of said storage media and writing said data to said corresponding locations in a second one of said storage media while maintaining access to at least said first storage medium for said I/O operations by said one or more of said host processors; b. comparing the data in said corresponding locations after said writing to determine if the data in said corresponding locations are identical; and c. repeating step a if the comparison of step b indicates that the data in said corresponding locations are not identical, otherwise terminating said management operation as to said storage locations.
Claim 14
Independent Claim
221 words
An apparatus for managing a shadow set of storage media accessible by one or more host processors for I/O operations that include writing data thereto, each one of said storage media having storage locations at least some of which correspond to storage locations of another one of said storage media, comprising: means for carrying out successive comparisons of data stored in said corresponding locations of said plurality of said storage media, respectively; and means, responsive to said comparisons, for performing a management operation on at least one of said storage media, said management operation comprising, for each of said corresponding locations where said comparisons indicated that the data in said corresponding locations were not identical; a. reading data from locations in a first one of said storage media and writing said data to said corresponding locations in a second one of said storage media while maintaining access to at least said first storage medium for said I/O operations by said one or more of said host processors; b. comparing the data in said corresponding locations after said writing to determine if the data in said corresponding locations are identical; and c. repeating step a if the comparison of step b indicates that the data in said corresponding locations are not identical, otherwise terminating said management operation as to said storage locations.
Claim 15
Dependent Claim
48 words
The method of claim 1 wherein each of said host processors will transmit any write requests to said storage media first to said first storage medium and, after said write request to said first storage medium has completed, will transmit said write request to said second storage medium.
Claim 16
Dependent Claim
34 words
The method of claim 1 wherein each of said host processors maintains a table including information that enables said host processor to determine if said data transfers are occurring between said of storage media.
Claim 17
Dependent Claim
23 words
The method of claim 10 wherein each of said storage media may be directly accessed by each of a plurality of host processors.
Claim 18
Dependent Claim
54 words
The method of claim 10 wherein each of said host processors will transmit any write requests to said storage media first to said one of said storage media and, after said write request to said one of said storage media has completed, will transmit said write request to said another of said storage media.
Claim 19
Dependent Claim
42 words
The method of claim 10 wherein each of said host processors maintains a table including information that enables said host processor to determine whether said management operation is being performed on one or more of said storage media in said shadow set.
Claim 20
Dependent Claim
40 words
The method of claim 10 wherein step B(b) comprises rereading said data from said locations in said one of said storage media and comparing said reread data to data in said corresponding locations in said another of said storage media.
Claim 21
Dependent Claim
31 words
The method of claim 10 wherein steps B(a) and B(b) are repeated recursively for the same corresponding locations until the data stored in said corresponding locations is determined to be identical.
Claim 22
Dependent Claim
54 words
The apparatus of claim 11 wherein each of said host processors will transmit any write requests to said storage media first to said one of said storage media and, after said write request to said one of said storage media has completed, will transmit said write request to said another of said storage media.
Claim 23
Dependent Claim
42 words
The apparatus of claim 11 wherein each of said host processors maintains a table including information that enables said host processor to determine whether said management operation is being performed on one or more of said storage media in said shadow set.
Claim 24
Dependent Claim
23 words
The apparatus of claim 11 wherein each of said storage media may be directly accessed by each of a plurality of host processors.
Claim 25
Dependent Claim
44 words
The apparatus of claim 11 wherein said management operation comprises rereading said data from said locations in said one of said storage media after said writing and comparing said reread data to data in said corresponding locations in said another of said storage media.
Claim 26
Dependent Claim
37 words
The apparatus of claim 11 wherein said means for performing said management operation repeats said reading and comparing recursively for the same corresponding locations until the data stored in said corresponding locations is determined to be identical.
References Cited (Backward Citations)
US3544777A
Cited
US3668644A
Cited
US4199810A
Cited
EP0026980A1
Cited
US4467421A
Cited
US4432057A
Cited
US4476526A
Cited
US4636946A
Cited
US4616312A
Cited
US4503534A
Cited
US4819154A
Cited
US4654819A
Cited
US4603406A
Cited
US4750106A
Cited
US4602368A
Cited
JPS59201297A
Cited
US4600990A
Cited
US4584681A
Cited
US4608687A
Cited
US4608688A
Cited
US4638424A
Cited
US4771375A
Cited
US4755928A
Cited
US4916605A
Cited
US4617475A
Cited
US4959774A
Cited
US4686620A
Cited
US4688219A
Cited
US4747038A
Cited
US4768193A
Cited
US4751639A
Cited
US4710870A
Cited
US4814971A
Cited
US4805095A
Cited
GB2188177A
Cited
EP0303856A2
Cited
US5060185A
Cited
US5089958A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-10 | 1996-11-09 | 1997-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-10 | 2000-11-09 | 2001-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-10 | 2004-11-09 | 2005-05-11 | $7700.00 | Window Closed / Lapsed |