Data consistency for mirroring updatable source data storage
First Claim
1. An information handling system for mirroring data, comprising:
- source data storage configured to store and update data;
first intermediate data storage configured to store data, said first intermediate data storage associated with said source data storage;
target data storage configured to store data;
second intermediate data storage configured to store data, said second intermediate data storage associated with said target data storage; and
mirroring control configured to conduct first cyclic incremental flashcopy of said source data storage, the beginning of each said first cyclic incremental flashcopy comprising a consistency point, said first cyclic incremental flashcopy copied to said first intermediate data storage and synchronously mirrored to said second intermediate data storage; and
to conduct a second cyclic incremental flashcopy of said second intermediate data storage to said target data storage, said second cyclic incremental flashcopy beginning in response to completion of said first cyclic incremental flashcopy;
the beginning of said second cyclic incremental flashcopy comprising commit of said consistency point;
wherein said mirroring control additionally comprises a loop representing said commit of said consistency point, initiating another first cyclic incremental flashcopy of said source data storage in response to said commit of said consistency point;
wherein said mirroring control additionally is configured to respond to an update write for said source data storage, to determine whether data of said source data storage to be overwritten by said update write is present at said first intermediate data storage and said second intermediate data storage;
if so, to allow said update write to be written to said source data storage, and to indicate said update write in a future flashcopy map.
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Accused Products
Abstract
An information handling system for mirroring data, in a fashion that is similar to asynchronous mirroring, but less complex in function. Source data storage for storing and updating data is provided, with first intermediate data storage, target data storage, second intermediate data storage, and mirroring control. The mirroring control conducts first cyclic incremental flashcopy of the source data storage, the beginning of each first cyclic incremental flashcopy comprising a consistency point. The first cyclic incremental flashcopy comprises copying data to be mirrored to the first intermediate storage and synchronously mirroring the data to the second intermediate data storage. A second cyclic incremental flashcopy of the second intermediate data storage is conducted to the target data storage, the second cyclic incremental flashcopy beginning in response to completion of the first cyclic incremental flashcopy; the beginning of the second cyclic incremental flashcopy comprising commit of the consistency point.
40 Citations
22 Claims
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1. An information handling system for mirroring data, comprising:
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source data storage configured to store and update data; first intermediate data storage configured to store data, said first intermediate data storage associated with said source data storage; target data storage configured to store data; second intermediate data storage configured to store data, said second intermediate data storage associated with said target data storage; and mirroring control configured to conduct first cyclic incremental flashcopy of said source data storage, the beginning of each said first cyclic incremental flashcopy comprising a consistency point, said first cyclic incremental flashcopy copied to said first intermediate data storage and synchronously mirrored to said second intermediate data storage; and
to conduct a second cyclic incremental flashcopy of said second intermediate data storage to said target data storage, said second cyclic incremental flashcopy beginning in response to completion of said first cyclic incremental flashcopy;
the beginning of said second cyclic incremental flashcopy comprising commit of said consistency point;
wherein said mirroring control additionally comprises a loop representing said commit of said consistency point, initiating another first cyclic incremental flashcopy of said source data storage in response to said commit of said consistency point;
wherein said mirroring control additionally is configured to respond to an update write for said source data storage, to determine whether data of said source data storage to be overwritten by said update write is present at said first intermediate data storage and said second intermediate data storage;
if so, to allow said update write to be written to said source data storage, and to indicate said update write in a future flashcopy map. - View Dependent Claims (2, 3, 4, 5)
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6. An information handling system for providing data for mirroring a source data storage to a target data storage, comprising:
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said source data storage configured to store and update data; first intermediate data storage configured to store data, said first intermediate data storage associated with said source data storage; and mirroring control configured to conduct first cyclic incremental flashcopy of said source data storage, the beginning of each said first cyclic incremental flashcopy comprising a consistency point, said first cyclic incremental flashcopy copied to said first intermediate data storage and synchronously mirrored to said second intermediate data storage for storing data, said second intermediate data storage associated with said target data storage; and a loop configured to initiate another first cyclic incremental flashcopy of said source data storage in response to a commit of said consistency point;
wherein said commit of said consistency point comprises the beginning of a second cyclic incremental flashcopy of said second intermediate data storage to said target data storage, said second cyclic incremental flashcopy beginning in response to completion of said first cyclic incremental flashcopy;wherein said mirroring control additionally is configured to respond to an update write for said source data storage, to determine whether data of said source data storage to be overwritten by said update write is present at said first intermediate data storage and said second intermediate data storage;
if so, to allow said update write to be written to said source data storage, and to indicate said update write in a future flashcopy map. - View Dependent Claims (7, 8, 9, 10)
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11. A method for mirroring data of updatable source data storage to target data storage, said source data storage for storing and updating data, comprising the steps of:
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conducting first cyclic incremental flashcopy of said source data storage, the beginning of each said first cyclic incremental flashcopy comprising a consistency point; said first cyclic incremental flashcopy copied to a first intermediate data storage and synchronously mirrored to a second intermediate data storage; a loop initiating another first cyclic incremental flashcopy of said source data storage in response to a commit of said consistency point;
wherein said commit of said consistency point comprises the beginning of a second cyclic incremental flashcopy of said second intermediate data storage to said target data storage, said second cyclic incremental flashcopy beginning in response to completion of said first cyclic incremental flashcopy; andin response to an update write for said source data storage, determining whether data of said source storage to be overwritten by said update write is present at said synchronously mirrored first intermediate data storage and said second intermediate data storage; if so, allowing said update write to be written to said source data storage, and indicating said update write in a future flashcopy map. - View Dependent Claims (12, 13, 14)
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15. A computer program product usable with at least one programmable computer processor having computer readable code embodied therein, said at least one programmable computer processor for controlling mirroring data of updatable source data storage to target data storage, said computer program product comprising:
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computer readable program code causing said at least one programmable computer processor to conduct first cyclic incremental flashcopy of said source data storage, the beginning of each said first cyclic incremental flashcopy comprising a consistency point;
said first cyclic incremental flashcopy copied to a first intermediate data storage and synchronously mirrored to a second intermediate data storage; andcomputer readable program code causing said at least one programmable computer processor to conduct a loop initiating another first cyclic incremental flashcopy of said source data storage in response to a commit of said consistency point;
wherein said commit of said consistency point comprises the beginning of a second cyclic incremental flashcopy of said second intermediate data storage to said target data storage, said second cyclic incremental flashcopy beginning in response to completion of said first cyclic incremental flashcopy; andcomputer readable program code causing said at least one programmable computer processor to, in response to an update write for said source data storage, determine whether data of said source data storage to be overwritten by said update write is present at said synchronously mirrored first intermediate data storage and said second intermediate data storage; if so, allow said update write to be written to said source data storage, and indicate said update write in a future flashcopy map. - View Dependent Claims (16, 17, 18)
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19. A mirroring controller configured to control mirroring data of updatable source data storage to target data storage, said source data storage for storing and updating data;
- said mirroring controller comprising;
mirroring control configured to conduct first cyclic incremental flashcopy of said source data storage, the beginning of each said first cyclic incremental flashcopy comprising a consistency point, said first cyclic incremental flashcopy copied to a first intermediate data storage for storing data; and
synchronously mirrored to a second intermediate data storage for storing data; and
, to conduct a loop initiating another first cyclic incremental flashcopy of said source data storage in response to a commit of said consistency point;
wherein said commit of said consistency point comprises the beginning of a second cyclic incremental flashcopy of said second intermediate data storage to said target data storage, said second cyclic incremental flashcopy beginning in response to completion of said first cyclic incremental flashcopy;
wherein said mirroring control additionally is configured to respond to an update write for said source data storage, determining whether data of said source data storage to be overwritten by said update write is present at said first intermediate data storage and said second intermediate data storage;
if so, allowing said update write to be written to said source data storage, and indicating said update write in a future flashcopy map. - View Dependent Claims (20, 21, 22)
- said mirroring controller comprising;
Specification