# US 10,372,548 B2 · Copying data from multiple point-in-time copies to a log storage to use to roll-back a source storage > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,372,548 B2 - Document ID: US10372548B2 - Status: Granted - Kind: B2 - Application number: 15/354,952 - Filed: 2016-11-17 - Published: 2018-05-17 - Granted: 2019-08-06 - Earliest claimed: 2016-11-17 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Theresa M. Brown; Nicolas M. Clayton; Gregory E. McBride; Carol S. Mellgren; David C. Reed - Web page: https://patentgrep.com/patent/US10372548B2 ## CPC - G06F 11/1448: {Management of the data involved in backup or backup restore} - G06F 11/1471: involving logging of persistent data for recovery - G06F 2201/84: Using snapshots, i.e. a logical point-in-time copy of the data - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Provided are a computer program product, system, and method for copying data from multiple point-in-time copies to a log storage to use to roll-back a source storage managing point-in-time copies of a source storage. A plurality of point-in-time copies of a source storage at different point-in-times are established. In response to receiving writes to the source storage after establishing each of the point-in-time copies, point-in-time data in the source storage is copied, before being updated by the received writes, to a log storage, wherein the log storage stores point-in-time data for multiple of the point-in-time copies. The log storage is used to roll-back the source storage to a selected point-in-time of one of the point-in-time copies. ## Claims ### Claim 1 A computer program product for managing point-in-time copies of a source storage, wherein the computer program product comprises a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause operations, the operations comprising: establishing a plurality of point-in-time copies of a source storage at different point-in-times; in response to receiving writes to the source storage after establishing each of the point-in-time copies, copying point-in-time data in the source storage, before being updated by the received writes, to a log storage, wherein the log storage stores point-in-time data for multiple of the point-in-time copies; for each of the established point-in-time copies, including in recovery metadata an entry including a first location and a last location in the log storage having point-in-time data for the point-in-time copy; and copying the point-in-time data to the source storage from the first location through the last location in the log storage indicated in the entry in the recovery metadata for each point-in-time copy to roll-back the source storage to a selected point-in-time of one of the point-in-time copies. ### Claim 2 (depends on 1) The computer program product of claim 1, wherein for each instance of the point-in-time data copied to the log storage, including metadata in the log storage indicating a source storage location in the source storage from which the point-in-time data was copied, wherein the point-in-time data is copied from the log storage to the source storage location in the source storage indicated in the log storage for the point-in-time data. ### Claim 3 (depends on 1) The computer program product of claim 1, wherein the point-in-time data is written to the log storage at sequential storage locations in an order in which the point-in-time data was updated at the source storage, wherein copying the point-in-time data to the source storage comprises applying the point-in-time data from a most recent written location in the log storage through sequential locations in the log storage having point-in-time data from a most recent point-in-time copy through the point-in-time copy of the selected point-in-time. ### Claim 4 (depends on 1) The computer program product of claim 1, wherein the operations further comprise: creating a recovery point-in-time copy of the source storage; and copying, to a recovery storage for the recovery point-in-time copy, the point-in-time data in the log storage from point-in-time copies for points-in-time greater than and equal to the selected point-in-time. ### Claim 5 (depends on 4) The computer program product of claim 4, wherein the operations further comprise: indicating, in a change recording data structure for the recovery point-in-time copy, that storage locations in the recovery storage to which the point-in-time data was applied have been updated. ### Claim 6 (depends on 4) The computer program product of claim 4, wherein the operations further comprise: determining whether data in the recovery storage is valid after copying the point-in-time data in the log storage from all the point-in-time copies used in the roll-back of the source storage; and in response to determining that the data in the recovery storage is not valid, performing: selecting a new point-in-time for one of the point-in-time copies earlier in time than a point-in-time used to create the recovery point-in-time; creating a new recovery point-in-time copy of the source storage having a new recovery storage; copying point-in-time data from storage locations in the source storage that are updated after creating the new recovery point-in-time copy to the new recovery storage; and applying, to the new recovery storage, the point-in-time data in the log storage from point-in-time copies for points-in-time greater than and equal to the selected new point-in-time. ### Claim 7 (depends on 4) The computer program product of claim 4, wherein the operations further comprise: determining whether data in the recovery storage is valid after copying the point-in-time data in the log storage from all the point-in-time copies used in the roll-back of the source storage; in response to determining that the data in the recovery storage is valid, performing: selecting a new recovery point-in-time greater in time than a recovery point-in-time; creating a new recovery point-in-time copy of the source storage having a new recovery storage; copying point-in-time data from storage locations in the source storage that are updated after creating the new recovery point-in-time copy to the new recovery storage; and applying, to the new recovery storage, the point-in-time data in the log storage from point-in-time copies for points-in-time greater than and equal to the selected new recovery point-in-time. ### Claim 8 (depends on 1) The computer program product of claim 1, wherein the operations further comprise: iteratively creating recovery point-in-time copies of the source storage for recovery point-in-times by applying, to a recovery storage for each of the recovery point-in-time copies, the point-in-time data in the log storage from point-in-time copies for points-in-time greater than and equal to one of the recovery point-in-times to determine one of the recovery point-in-time copies having valid data in the recovery storage as of a determined recovery point-in-time between two recovery point-in-time copies having invalid data; and applying the point-in-time data from the recovery storage for the determined recovery point-in-time copy to the source storage to return to the determined recovery point-in-time at which the source storage had valid data. ### Claim 9 A system for managing point-in-time copies of a source storage, comprising: processor; and a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause operations, the operations comprising: establishing a plurality of point-in-time copies of a source storage at different point-in-times; in response to receiving writes to the source storage after establishing each of the point-in-time copies, copying point-in-time data in the source storage, before being updated by the received writes, to a log storage, wherein the log storage stores point-in-time data for multiple of the point-in-time copies; for each of the established point-in-time copies, including in recovery metadata an entry including a first location and a last location in the log storage having point-in-time data for the point-in-time copy; and copying the point-in-time data to the source storage from the first location through the last location in the log storage indicated in the entry in the recovery metadata for each point-in-time copy to roll-back the source storage to a selected point-in-time of one of the point-in-time copies. ### Claim 10 (depends on 9) The system of claim 9, wherein for each instance of the point-in-time data copied to the log storage, including metadata in the log storage indicating a source storage location in the source storage from which the point-in-time data was copied, wherein the point-in-time data is copied from the log storage to the source storage location in the source storage indicated in the log storage for the point-in-time data. ### Claim 11 (depends on 9) The system of claim 9, wherein the point-in-time data is written to the log storage at sequential storage locations in an order in which the point-in-time data was updated at the source storage, wherein the copying the point-in-time data to the source storage comprises applying the point-in-time data from a most recent written location in the log storage through sequential locations in the log storage having point-in-time data from a most recent point-in-time copy through the point-in-time copy of the selected point-in-time. ### Claim 12 (depends on 9) The system of claim 9, wherein the operations further comprise: creating a recovery point-in-time copy of the source storage; and copying, to a recovery storage for the recovery point-in-time copy, the point-in-time data in the log storage from point-in-time copies for points-in-time greater than and equal to the selected point-in-time. ### Claim 13 (depends on 12) The system of claim 12, wherein the operations further comprise: indicating, in a change recording data structure for the recovery point-in-time copy, that storage locations in the recovery storage to which the point-in-time data was applied have been updated. ### Claim 14 (depends on 9) The system of claim 9, wherein the operations further comprise: iteratively creating recovery point-in-time copies of the source storage for recovery point-in-times by applying, to a recovery storage for each of the recovery point-in-time copies, the point-in-time data in the log storage from point-in-time copies for points-in-time greater than and equal to one of the recovery point-in-times to determine one of the recovery point-in-time copies having valid data in the recovery storage as of a determined recovery point-in-time between two recovery point-in-time copies having invalid data; and applying the point-in-time data from the recovery storage for the determined recovery point-in-time copy to the source storage to return to the determined recovery point-in-time at which the source storage had valid data. ### Claim 15 A method for managing point-in-time copies of a source storage, comprising: establishing a plurality of point-in-time copies of a source storage at different point-in-times; in response to receiving writes to the source storage after establishing each of the point-in-time copies, copying point-in-time data in the source storage, before being updated by the received writes, to a log storage, wherein the log storage stores point-in-time data for multiple of the point-in-time copies; for each of the established point-in-time copies, including in recovery metadata an entry including a first location and a last location in the log storage having point-in-time data for the point-in-time copy; and copying the point-in-time data to the source storage from the first location through the last location in the log storage indicated in the entry in the recovery metadata for each point-in-time copy to roll-back the source storage to a selected point-in-time of one of the point-in-time copies. ### Claim 16 (depends on 15) The method of claim 15, wherein for each instance of the point-in-time data copied to the log storage, including metadata in the log storage indicating a source storage location in the source storage from which the point-in-time data was copied, wherein the point-in-time data is copied from the log storage to the source storage location in the source storage indicated in the log storage for the point-in-time data. ### Claim 17 (depends on 15) The method of claim 15, wherein the point-in-time data is written to the log storage at sequential storage locations in an order in which the point-in-time data was updated at the source storage, wherein the copying the point-in-time data to the source storage comprises applying the point-in-time data from a most recent written location in the log storage through sequential locations in the log storage having point-in-time data from a most recent point-in-time copy through the point-in-time copy of the selected point-in-time. ### Claim 18 (depends on 15) The method of claim 15, further comprising: creating a recovery point-in-time copy of the source storage; and copying, to a recovery storage for the recovery point-in-time copy, the point-in-time data in the log storage from point-in-time copies for points-in-time greater than and equal to the selected point-in-time. ### Claim 19 (depends on 18) The method of claim 18, further comprising: indicating, in a change recording data structure for the recovery point-in-time copy, that storage locations in the recovery storage to which the point-in-time data was applied have been updated. ### Claim 20 (depends on 15) The method of claim 15, further comprising: iteratively creating recovery point-in-time copies of the source storage for recovery point-in-times by applying, to a recovery storage for each of the recovery point-in-time copies, the point-in-time data in the log storage from point-in-time copies for points-in-time greater than and equal to one of the recovery point-in-times to determine one of the recovery point-in-time copies having valid data in the recovery storage as of a determined recovery point-in-time between two recovery point-in-time copies having invalid data; and applying the point-in-time data from the recovery storage for the determined recovery point-in-time copy to the source storage to return to the determined recovery point-in-time at which the source storage had valid data.