Patent US2755161A successfully refreshed from Google Patents.
US5233618A
Expired / Lapsed
US
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Data correcting applicable to redundant arrays of independent disks
Assignee: EMC Corp
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Filing: 1990-03-02
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Granted: 1993-08-03
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Expires: 2010-03-02
Abstract
Abstract Methods and apparatus are provided for detecting and correcting various data errors that may arise in a mass data storage apparatus comprising a set of physical mass storage devices operating as one or more larger logical mass storage devices. A method and apparatus is provided for detecting and reconstructing incorrectly routed data. A method and apparatus is also provided for detecting when one or more physical devices fails to write a block of data, and for reconstructing lost data.
Inventors
- 👤 Joseph S. Glider
- 👤 David T. Powers
- 👤 Thomas E. Idleman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:02
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G06F11/00; G06F11/07; G06F11/08; G06F11/10; G06F11/1076; G11; G11C; G11C29/00; G11C29/70; G11C29/88; G06F11/16; G06F11/1608; G06F11/1612; G06F2211/00; G06F2211/10; G06F2211/1002; G06F2211/1007; G06F2211/104; G06F3/0668; G06F3/0671; G06F3/0673
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
267 words
A mass data storage apparatus comprising: a set of physical mass storage devices operatively interconnected so as to function as at least one logical mass storage device; means for reading blocks of data from and writing blocks of data to the set of physical mass storage devices; and means for validating blocks of data read from or written to the set of physical mass storage devices, wherein the validating means comprises mean for performing the following functions: (a) when writing a block of data to a device of the set, storing with the block of data on the device, information identifying the intended logical storage location for the block of data, and, when reading a block of data from a device of the set, detecting whether the block of data that is read was misdirected within the apparatus when written by comparing the identifying information stored with the read block of data and a logical address associated with the logical storage location form which the block of data is read; and (b) when writing a block of data to a device of the set, storing with the block of data on the device, information identifying the write operation by which the block of data is written and storing with a selected block of data on another device of the set, information identifying the same write operation, and, when reading the block of data, detecting whether the identified write operation was completed by comparing the identifying information stored with the read block of data to the identifying information stored with the selected block of data on another device.
Claim 2
Dependent Claim
267 words
A mass data storage apparatus comprising: a set of physical mass storage devices operatively interconnected so as to function as at least one logical mass storage device; means for reading blocks of data from and writing blocks of data to the set of physical mass storage devices; and means for validating blocks of data read from or written to the set of physical mass storage devices, wherein the validating means comprises mean for performing the following functions: (a) when writing a block of data to a device of the set, storing with the block of data on the device, information identifying the intended logical storage location for the block of data, and, when reading a block of data from a device of the set, detecting whether the block of data that is read was misdirected within the apparatus when written by comparing the identifying information stored with the read block of data and a logical address associated with the logical storage location form which the block of data is read; and (b) when writing a block of data to a device of the set, storing with the block of data on the device, information identifying the write operation by which the block of data is written and storing with a selected block of data on another device of the set, information identifying the same write operation, and, when reading the block of data, detecting whether the identified write operation was completed by comparing the identifying information stored with the read block of data to the identifying information stored with the selected block of data on another device.
Claim 3
Dependent Claim
168 words
In a mass data storage apparatus comprising a set of physical mass storage devices at least a plural number of which are operatively interconnected so as to function as a single logical data storage unit, the logical unit being operable in a transaction mode wherein data blocks stored in the logical unit may be individually modified, a method for detecting whether a write operation intended to modify a data block within the logical unit was completed, the method comprising: arranging the devices of the logical unit intended to store data blocks into groups such that the devices of each group are read and written in parallel; when modifying a data block on one device, storing a time stamp on the one device and other devices in the group indicating when the block of data was modified; and comparing the time stamp stored on the one device to the time stamps stored on the other devices of the group to determine if the time stamps correspond to one another.
Claim 4
Dependent Claim
168 words
In a mass data storage apparatus comprising a set of physical mass storage devices at least a plural number of which are operatively interconnected so as to function as a single logical data storage unit, the logical unit being operable in a transaction mode wherein data blocks stored in the logical unit may be individually modified, a method for detecting whether a write operation intended to modify a data block within the logical unit was completed, the method comprising: arranging the devices of the logical unit intended to store data blocks into groups such that the devices of each group are read and written in parallel; when modifying a data block on one device, storing a time stamp on the one device and other devices in the group indicating when the block of data was modified; and comparing the time stamp stored on the one device to the time stamps stored on the other devices of the group to determine if the time stamps correspond to one another.
Claim 5
Dependent Claim
168 words
A mass data storage apparatus comprising: a set of physical mass storage devices operatively interconnected so as to function as at least one logical mass storage device; means for reading blocks of data from and writing blocks of data to the set of physical mass storage devices; and means for validating blocks of data read from or written to the set of physical mass storage devices, wherein the validating means comprises means for, when writing a block of data to a device of the set, storing with the block of data on the device information identifying the write operation by which the block of data is written and storing with a selected block of data on another device of the set information identifying the same write operation, and, when reading the block of data, detecting whether the identified write operation was completed by comparing the identifying information stored with the read block of data to the identifying information stored with the selected block of data on another device.
Claim 6
Dependent Claim
168 words
A mass data storage apparatus comprising: a set of physical mass storage devices operatively interconnected so as to function as at least one logical mass storage device; means for reading blocks of data from and writing blocks of data to the set of physical mass storage devices; and means for validating blocks of data read from or written to the set of physical mass storage devices, wherein the validating means comprises means for, when writing a block of data to a device of the set, storing with the block of data on the device information identifying the write operation by which the block of data is written and storing with a selected block of data on another device of the set information identifying the same write operation, and, when reading the block of data, detecting whether the identified write operation was completed by comparing the identifying information stored with the read block of data to the identifying information stored with the selected block of data on another device.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-02 | 1997-02-01 | 1997-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-02 | 2001-02-01 | 2001-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-02 | 2005-02-01 | 2005-08-03 | $7700.00 | Window Closed / Lapsed |