Data recovery for virtual ordered writes for multiple storage devices
First Claim
1. A method of recovering data provided by a plurality of primary storage devices to a plurality of secondary storage devices, comprising:
- the secondary storage devices receiving data in chunks, each chunk having a sequence number associated therewith, wherein writes by the primary storage devices begun before a particular time are assigned a first sequence number and writes begun by the primary storage devices begun after the particular time are assigned a second sequence number different than the first sequence number and wherein switching of sequence numbers is coordinated between the primary storage devices;
for each of the secondary storage devices, discarding data corresponding to chunks for which all data thereof has not been received; and
for each of the secondary storage devices, restoring a chunk of data thereto wherein all of the chunks of data restored to the plurality of secondary storage devices have the same sequence number.
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Accused Products
Abstract
Recovering data provided in chunks to a plurality of secondary storage devices includes, for each of the secondary storage devices, discarding data corresponding chunks for which all data thereof has not been received, and, for each of the secondary storage devices, restoring a chunk of data thereto where all of the chunks of data restored to the plurality of secondary storage devices correspond to a particular transmission cycle of primary storage devices that provide data to the plurality of secondary storage devices. Recovering data may also include, following discarding and prior to restoring, for each of the plurality of secondary storage devices having two different chunks, waiting for external intervention to indicate whether to restore a particular one of the chunks. The external intervention may be provided by a host computer that is proximate to at least one of the secondary storage devices or may be provided by a host computer that is proximate to at least one of the primary storage computers.
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Citations
18 Claims
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1. A method of recovering data provided by a plurality of primary storage devices to a plurality of secondary storage devices, comprising:
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the secondary storage devices receiving data in chunks, each chunk having a sequence number associated therewith, wherein writes by the primary storage devices begun before a particular time are assigned a first sequence number and writes begun by the primary storage devices begun after the particular time are assigned a second sequence number different than the first sequence number and wherein switching of sequence numbers is coordinated between the primary storage devices; for each of the secondary storage devices, discarding data corresponding to chunks for which all data thereof has not been received; and for each of the secondary storage devices, restoring a chunk of data thereto wherein all of the chunks of data restored to the plurality of secondary storage devices have the same sequence number. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. Computer-readable medium containing computer software that recovers data provided by a plurality of primary storage devices to a plurality of secondary storage devices, comprising:
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executable code that receives data in chunks, each chunk having a sequence number associated therewith, wherein writes by the primary storage devices begun before a particular time are assigned a first sequence number and writes begun by the primary storage devices begun after the particular time are assigned a second sequence number different than the first sequence number and wherein switching of sequence numbers is coordinated between the primary storage devices; executable code that discards data corresponding to chunks for which all data thereof has not been received for each of the secondary storage devices; and executable code that restores a chunk of data thereto for each of the secondary storage devices, wherein all of the chunks of data restored to the plurality of secondary storage devices have the same sequence number. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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Specification