Recovering from a mistaken point-in-time copy restore
AssigneeInternational Business Machines Corporation
InventorsJoshua J. Crawford, Paul A. Jennas, II, Jason L. Peipelman, Matthew J. Ward
Life of this patent
Estimating the term…
Abstract
A method, system, and program product are provided for processing a host write operation during a recovery operation of a point-in-time copy restore. Provided are blocking the host write operation to the source volume based on whether a track on the source volume is copied to the target volume. A host and the point-in-time copy restore synchronize simultaneous access to the track using a track lock on track access, causing a requestor without the track lock to be queued until the track lock is available.
Claims16
A method for processing a host write operation during a recovery operation of a point-in-time copy restore, comprising:
- blocking the host write operation to a source volume based on whether a track on the source volume is copied to a target volume;
- wherein the host write operation and the point-in-time copy restore synchronize simultaneous access to the track on the source volume using a track lock on track access, and causing a requestor without the track lock to be queued until the track lock is available, wherein a state of the source volume and the state of the target volume as of an execution of the recovery operation is preserved, and wherein the recovery operation is reversible to the state of the source volume and the state of the target volume prior to the execution of the recovery operation;
- and
- in response to the recovery operation determining that the track on the source volume is not copied to the target volume:
- copying the track from the source volume to the target volume;
- setting a bit in a change recording bitmap on the source volume corresponding to a changed track;
- and
- completing the host write operation on the source volume.
A computer program product for processing a host write operation during a recovery operation of a point-in-time copy restore, comprising, program instructions embodied on a non-transitory computer readable storage medium, the program instructions executable by a processor to perform a method comprising:
- blocking the host write operation to a source volume based on whether a track on the source volume is copied to a target volume;
- and
- wherein a host and the point-in-time copy restore synchronize simultaneous access to the track using a track lock on track access, and causing a requestor without the track lock to be queued until the track lock is available.
A computer system for processing a host write operation during a recovery operation of a point-in-time copy restore, comprising:
- one or more processors, one or more tangible computer-readable storage devices, and a plurality of program instructions stored on at least one of the one or more tangible computer-readable storage devices for execution by at least one of the one or more processors, the plurality of program instructions comprising:
- blocking the host write operation to a source volume based on whether a track on the source volume is copied to a target volume;
- and
- wherein a state of the source volume and the state of the target volume as of the execution of the recovery operation is preserved, and wherein the recovery operation is reversible to the state of the source volume and the state of the target volume prior to the execution of the recovery operation;
- wherein a host and the point-in-time copy restore synchronize simultaneous access to the track using a track lock on track access, and causing a requestor without the track lock to be queued until the track lock is available;
- and
- wherein in response to the recovery operation determining that the track on the source volume is not copied to the target volume:
- copying the track from the source volume to the target volume;
- setting a bit in a change recording bitmap on the source volume corresponding to a changed track;
- and
- completing the host write operation on the source volume.
Dependencies are inferred from the claim text.