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 region is marked if a copy of data is available on the disaster recovery storage volume;
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;
receiving an update for a region of the disaster recovery storage volume from a primary system; and
in response to determining no marking exists in the record of regions for the region of the disaster recovery storage volume, discarding the update, andwherein the marking indicates that a copy of data is available on the disaster recovery storage volume.
1 Assignment
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Accused Products
Abstract
Systems, methods, and computer products for copy-on-read processes in disaster recovery include: making a disaster recovery storage volume available for read access before all data from a corresponding primary storage volume has been copied to a disaster recovery storage volume; maintaining a record of regions of the disaster recovery storage volume; 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; obtaining data unavailable at the disaster recovery storage volume 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.
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Citations
21 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 region is marked if a copy of data is available on the disaster recovery storage volume; 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; receiving an update for a region of the disaster recovery storage volume from a primary system; and in response to determining no marking exists in the record of regions for the region of the disaster recovery storage volume, discarding the update, and wherein the marking indicates that a copy of data is available on the disaster recovery storage volume. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. 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 region is marked if a copy of data is available on the disaster recovery storage volume; 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 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 for the regions of the obtained data; and an update component configured to; receive an update for a region of the disaster recovery storage volume from a primary system; and in response to determining no marking for the region exists in the record of regions, discarding the update, and wherein the marking indicates that a copy of data is available on the disaster recovery storage volume. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. 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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make, 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; maintain, by the computer, a record of regions of the disaster recovery storage volume wherein a region is marked if a copy of data is available on the disaster recovery storage volume; in response to receipt of a read request for data at the disaster recovery system; look up the record of regions to determine available data for the read request;
read any available data from the disaster recovery storage volume;
obtain, from the corresponding primary storage volume, any data unavailable at the disaster recovery storage volume;update the disaster recovery storage volume with the obtained data; supply the obtained data to the read request; and update the record of regions of the disaster recovery storage volume for the regions of the obtained data; and receive an update for a region of the disaster recovery storage volume from a primary system; and in response to determining no marking exists in the record of regions for the region of the disaster recovery storage volume, discard the update, and wherein the marking indicates that a copy of data is available on the disaster recovery storage volume. - View Dependent Claims (21)
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Specification