Remote Backup Copy in Asynchronous Replication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional data replication methods face challenges in creating remote backup copies in asynchronous replication arrangements with long cycle times, which can exceed the maximum freeze time of applications, making it difficult to maintain data consistency and integrity.
Innovation Solution
The implementation of a cycle-based asynchronous replication process that includes a consistency group replication from a source storage system to a target storage system over multiple asynchronous replication cycles, with a processing device initiating a write hold state and directing the generation of a remote backup copy, ensuring data consistency and allowing the system to exit the write hold state upon completion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If asynchronous replication with long cycle times is used, then remote backup copies can be created, but data consistency cannot be guaranteed because the cycle time exceeds application freeze time
Solution Approach 1:
The system initiates a write hold state on the source storage system before starting the backup copy creation process. This preliminary action freezes data writes in advance, ensuring that the data remains consistent during the replication cycle. The write hold state is maintained until the backup copy is successfully created, preventing any data changes that would compromise consistency.
Solution Approach 2:
The patent introduces an intermediary control mechanism that coordinates between the source storage system, target storage system, and backup copy creation process. This intermediary manages the write hold state transitions and ensures proper synchronization, acting as a mediator that resolves the conflict between long replication cycles and data consistency requirements.
2Reliability
If a write hold state is initiated to ensure data consistency, then data integrity is maintained, but application operations are blocked during the freeze period
Solution Approach 1:
The write hold state is implemented dynamically rather than statically. The system transitions between active and hold states based on the backup copy creation progress. This dynamic approach allows the system to minimize the duration of the write hold state while still ensuring data consistency, thereby reducing the impact on application productivity.
Solution Approach 2:
The backup copy creation process is designed to be self-managing within the storage system. Once the write hold state is initiated, the system automatically coordinates the data replication and copy creation without requiring continuous external intervention. This self-service mechanism reduces the overall time the application operations are blocked.
Data Source
AI summary
An apparatus comprises at least one processing device comprising a processor coupled to a memory. The at least one processing device is configured to initiate generation of a remote backup copy for a consistency group subject to replication from a first storage system to a second storage system, and responsive to receipt of a freeze indication from at least one application that utilizes the consistency group in the first storage system, to direct the first storage system to enter a write hold state. The at least one processing device is further configured to direct the second storage system to generate the remote backup copy from the consistency group as currently replicated from the first storage system to the second storage system, and responsive to receipt of a copy complete indication from the second storage system, to direct the first storage system to exit the write hold state.