# US 8,751,758 B2 · Delayed instant copy operation for short-lived snapshots > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,751,758 B2 - Document ID: US8751758B2 - Status: Granted - Kind: B2 - Application number: 13/175,680 - Filed: 2011-07-01 - Published: 2013-01-03 - Granted: 2014-06-10 - Earliest claimed: 2011-07-01 - Assignees: International Business Machines Corporation - Applicants: Ehood Garmiza; Eyal Lotem; Assaf Nitzan; Eliyahu Weissbrem - Inventors: Ehood Garmiza; Eyal Lotem; Assaf Nitzan; Eliyahu Weissbrem - Web page: https://patentgrep.com/patent/US8751758B2 ## CPC - G06F 16/128: {Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion (error detection or correction of the data by redundancy in operations or in hardware G06F11/14, G06F11/16)} - G06F 3/0614: {Improving the reliability of storage systems} - G06F 3/065: {Replication mechanisms} - G06F 3/0674: {Disk device} - G06F 11/2074: {Asynchronous techniques} - 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 A method, including defining a snapshot referencing a source partition of a storage volume on a storage device, and receiving a request to write a block of data to the source partition. Upon receiving the write request, a delayed instant copy operation is initiated by allocating a target partition on the storage device and replacing, in the storage volume, the source partition with the target partition. A definition of a condition for completion of the delayed instant copy operation is received, and the delayed instant copy operation is completed upon the condition being met. ## Claims ### Claim 1 A method, comprising: defining a snapshot referencing a source partition of a storage volume on a storage device; receiving a request to write a block of data to the source partition; initiating a delayed instant copy operation upon receiving the write request, by allocating a target partition on the storage device and replacing, in the storage volume, the source partition with the target partition; receiving a definition of a condition for completion of the delayed instant copy operation; wherein the condition comprises a cancellation of the snapshot; and completing the delayed instant copy operation upon the condition being met. ### Claim 2 (depends on 1) The method according to claim 1, wherein completing the delayed instant copy operation comprises: releasing the target partition; deleting the snapshot; and restoring the source partition to the volume. ### Claim 3 (depends on 1) The method according to claim 1, wherein the condition is selected from a list consisting of the delayed instant copy operation being active for a specific time period and a memory storing the received block of data reaching a specific threshold. ### Claim 4 (depends on 3) The method according to claim 3, wherein completing the delayed instant copy operation comprises: loading the source partition to a memory buffer; updating the memory buffer with the block of data; and storing the updated buffer to the target partition. ### Claim 5 (depends on 1) The method according to claim 1, wherein receiving the request comprises storing the block of data to a cache in a volatile memory. ### Claim 6 (depends on 1) The method according to claim 1, wherein the allocated target partition on the storage device is not in the storage volume. ### Claim 7 An apparatus, comprising: a storage device; and a processor configured to define a snapshot referencing a source partition of a storage volume on the storage device, to receive a request to write a block of data to the source partition, to initiate a delayed instant copy operation upon receiving the write request, by allocating a target partition on the storage device and replacing, in the storage volume, the source partition with the target partition, to receive a definition of a condition for completion of the delayed instant copy operation, the condition comprising a cancellation of the snapshot, and to complete the delayed instant copy operation upon the condition being met. ### Claim 8 (depends on 7) The apparatus according to claim 7, wherein the processor is configured to complete the delayed instant copy operation by releasing the target partition, deleting the snapshot, and restoring the source partition to the volume. ### Claim 9 (depends on 7) The apparatus according to claim 7, wherein the processor is configured to select the condition from a list consisting of the delayed instant copy operation being active for a specific time period and a memory storing the received block of data reaching a specific threshold. ### Claim 10 (depends on 9) The apparatus according to claim 9, wherein the processor is configured to complete the delayed instant copy operation by loading the source partition to a memory buffer, updating the memory buffer with the block of data, and storing the updated buffer to the target partition. ### Claim 11 (depends on 7) The apparatus according to claim 7, wherein the processor is configured to receive the request by storing the block of data to a cache in a volatile memory. ### Claim 12 (depends on 7) The apparatus according to claim 7, wherein the allocated target partition on the storage device is not in the storage volume. ### Claim 13 A computer program product, the computer program product comprising: a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising: computer readable program code configured to define a snapshot referencing a source partition of a storage volume on a storage device; computer readable program code configured to receive a request to write a block of data to the source partition; computer readable program code configured to initiate a delayed instant copy operation upon receiving the write request, by allocating a target partition on the storage device and replacing, in the storage volume, the source partition with the target partition; computer readable program code configured to receive a definition of a condition for completion of the delayed instant copy operation; the condition comprising a cancellation of the snapshot; and computer readable program code configured to complete the delayed instant copy operation upon the condition being met. ### Claim 14 (depends on 13) The computer program product according to claim 13, wherein the computer readable program code is configured to complete the delayed instant copy operation by releasing the target partition, deleting the snapshot, and restoring the source partition to the volume. ### Claim 15 (depends on 13) The computer program product according to claim 13, wherein the computer readable program code is configured to select the condition from a list consisting of the delayed instant copy operation being active for a specific time period and a memory storing the received block of data reaching a specific threshold. ### Claim 16 (depends on 15) The computer program product according to claim 15, wherein the computer readable program code is configured to complete the delayed instant copy operation by loading the source partition to a memory buffer, updating the memory buffer with the block of data, and storing the updated buffer to the target partition. ### Claim 17 (depends on 13) The computer program product according to claim 13, wherein the computer readable program code is configured to receive the request by storing the block of data to a cache in a volatile memory. ### Claim 18 (depends on 13) The computer program product according to claim 13, wherein the allocated target partition on the storage device is not in the storage volume.