Copy-on-read process in disaster recovery
First Claim
1. A method for copy-on-read process in disaster recovery, comprising:
- making a disaster recovery storage volume available at a disaster recovery system for read access before all data from a corresponding primary storage volume has been copied to the disaster recovery storage volume;
maintaining a record of regions of the disaster recovery storage volume, wherein a given region of the disaster recovery storage volume is marked if a copy of data is available on the disaster recovery storage volume;
maintaining a record of regions of the corresponding primary storage volume, wherein a given region of the corresponding primary storage volume is marked when original data of the given region is sent to a disaster recovery system; and
performing an initial synchronization process, the initial synchronization process including;
determining, using the record of regions of the corresponding primary storage volume, that new writes to the marked region of the corresponding primary storage volume should be immediately replicated to the disaster recovery system; and
in response to receiving a read request for data at the disaster recovery system;
looking up the record of regions of the disaster recovery storage volume to determine available data for the read request;
reading any available data from the disaster recovery storage volume;
for any data unavailable at the disaster recovery storage volume, obtaining the unavailable data from the corresponding primary storage volume;
updating the disaster recovery storage volume with the obtained data;
supplying the obtained data to the read request; and
updating the record of regions of the disaster recovery storage volume for the regions of the obtained data;
wherein the corresponding primary storage volume is located at a primary site; and
wherein the disaster recovery storage volume is located at a disaster recovery site remote from the primary site.
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Accused Products
Abstract
Systems and program products are configured to perform a method for copy-on-read in disaster recovery (DR). The method includes: making a DR storage volume available at a DR system for read access before all data from a corresponding primary storage volume has been copied to the DR storage volume; maintaining a record of regions of the DR storage volume; and responsive to receiving a read request for data at the DR system: looking up the record of regions of the DR storage volume to determine available data for the read request; reading any available data from the DR storage volume; for any data unavailable at the DR storage volume, obtaining the unavailable data from the corresponding primary storage volume; updating the DR storage volume with obtained data; supplying obtained data to the read request; and updating the record of regions of the DR storage volume for regions of obtained data.
21 Citations
19 Claims
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1. A method for copy-on-read process in disaster recovery, comprising:
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making a disaster recovery storage volume available at a disaster recovery system for read access before all data from a corresponding primary storage volume has been copied to the disaster recovery storage volume; maintaining a record of regions of the disaster recovery storage volume, wherein a given region of the disaster recovery storage volume is marked if a copy of data is available on the disaster recovery storage volume; maintaining a record of regions of the corresponding primary storage volume, wherein a given region of the corresponding primary storage volume is marked when original data of the given region is sent to a disaster recovery system; and performing an initial synchronization process, the initial synchronization process including;
determining, using the record of regions of the corresponding primary storage volume, that new writes to the marked region of the corresponding primary storage volume should be immediately replicated to the disaster recovery system; andin response to receiving a read request for data at the disaster recovery system; looking up the record of regions of the disaster recovery storage volume to determine available data for the read request; reading any available data from the disaster recovery storage volume; for any data unavailable at the disaster recovery storage volume, obtaining the unavailable data from the corresponding primary storage volume; updating the disaster recovery storage volume with the obtained data; supplying the obtained data to the read request; and updating the record of regions of the disaster recovery storage volume for the regions of the obtained data; wherein the corresponding primary storage volume is located at a primary site; and wherein the disaster recovery storage volume is located at a disaster recovery site remote from the primary site. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A system for copy-on-read process in disaster recovery, comprising:
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a disaster recovery storage volume comprising a computer readable storage medium available at a disaster recovery system for read access before all data from a corresponding primary storage volume has been copied to the disaster recovery storage volume; a record of regions of the disaster recovery storage volume, wherein a given region of the disaster recovery storage volume is marked if a copy of data is available on the disaster recovery storage volume; a record of regions of the corresponding primary storage volume, wherein a given region of the corresponding primary storage volume is marked when original data of the given region is sent to a disaster recovery system; a primary replication component configured to perform a replication process including determining, using the record of regions of the corresponding primary storage volume, that new writes to the marked region of the corresponding primary storage volume should be immediately replicated to the disaster recovery system; and a disaster recovery replication component configured to receive a read request for data at the disaster recovery system, the disaster recovery replication component further comprising; a disaster recovery record look up component configured to look up the record of regions of the disaster recovery storage volume to determine available data for the read request; a disaster recovery read component configured to read any available data from the disaster recovery storage volume; and a primary copy component further comprising; a primary message component configured to obtain any unavailable data from the corresponding primary storage volume; a disaster recovery write component configured to update the disaster recovery storage volume with the obtained data; a host reply component configured to supply the obtained data to the read request; and a record mark-up component configured to update the record of regions of the disaster recovery storage volume for the regions of the obtained data; wherein the primary storage volume is located at a primary site; and wherein the disaster recovery storage volume is located at a disaster recovery site remote from the primary site. - View Dependent Claims (14, 15, 16, 17)
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18. A computer program product for copy-on-read process in disaster recovery, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions readable/executable by a computer to cause the computer to perform a method comprising:
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making, by the computer, a disaster recovery storage volume available at a disaster recovery system for read access before all data from a corresponding primary storage volume has been copied to the disaster recovery storage volume; maintaining, by the computer, a record of regions of the disaster recovery storage volume, wherein a given region of the disaster recovery storage volume is marked if a copy of data is available on the disaster recovery storage volume; maintaining, by the computer, a record of regions of the corresponding primary storage volume, wherein a given region of the disaster recovery storage volume is marked when original data of the given region is sent to a disaster recovery system; performing an initial synchronization process, the initial synchronization process including;
determining, by the computer, and using the record of regions of the corresponding primary storage volume, that new writes to the marked region of the corresponding primary storage volume should be immediately replicated to the disaster recovery system; andin response to receiving a read request for data at the disaster recovery system; looking up the record of regions to determine available data for the read request; reading any available data from the disaster recovery storage volume; obtaining any unavailable data from the corresponding primary storage volume; updating the disaster recovery storage volume with the obtained data; supplying the obtained data to the read request; and updating the record of regions of the disaster recovery storage volume for the regions of the obtained data; wherein the primary storage volume is located at a primary site; and wherein the disaster recovery storage volume is located at a disaster recovery site remote from the primary site. - View Dependent Claims (19)
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Specification