Storage Control Device Partial Copy Data Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing data redundancy techniques, such as SnapOPC, consume large disk capacity and increase storage costs due to the need for frequent generation of equivalent copies to ensure data recovery in case of hardware failures, while only providing data at the time of equivalent copy initiation.
Innovation Solution
A control device and method that perform partial and equivalent copy processes, managing association and recovery information to read data from either partially copied or equivalent volumes, allowing data to be read from the appropriate source even in case of hardware failures without the need for frequent equivalent volume generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an equivalent copy (full backup) is generated every time SnapOPC is performed to ensure data recovery, then data recovery reliability is improved, but disk capacity consumption increases and storage cost increases
Solution Approach 1:
The patent segments the backup strategy into two distinct components: SnapOPC for partial/differential data copying to reduce storage consumption, and selective EC for full equivalent copying only when necessary for data recovery. This segmentation allows the system to maintain reliability while reducing overall disk capacity consumption by avoiding redundant full copies.
Solution Approach 2:
Instead of performing excessive full equivalent copies every time SnapOPC is executed, the patent applies partial action by selectively performing EC only when differential data copying is insufficient for complete data recovery. This reduces unnecessary storage consumption while maintaining adequate recovery capability.
2Quantity of substance
If SnapOPC is used to reduce physical capacities of duplicated volumes, then disk capacity consumption is reduced, but data recovery capability is worsened because data at the time of hardware failure cannot be restored
Solution Approach 1:
The patent performs preliminary EC before SnapOPC to establish a baseline full copy. This preliminary action ensures that even if SnapOPC differential copying fails to capture all necessary data due to hardware failure, the pre-established EC provides a complete recovery source, thereby maintaining data recovery capability while using SnapOPC for ongoing efficient backups.
Solution Approach 2:
The patent introduces EC as an intermediary mechanism that bridges the gap between SnapOPC's space efficiency and complete data recovery requirements. By selectively combining EC and SnapOPC, the system achieves both reduced disk capacity consumption and maintained data recovery capability.
3Reliability
If EC is performed to generate a complete duplicate for data recovery, then data recovery capability is improved, but the data is only from the time point when EC is started and cannot recover data from SnapOPC start time
Solution Approach 1:
The patent merges EC and SnapOPC into a coordinated hybrid backup system where EC provides the baseline full copy and SnapOPC captures subsequent differential changes. This combination ensures both complete data recovery capability and continuous data time coverage, as SnapOPC preserves data from its start time while EC provides the foundational complete duplicate.
Data Source
AI summary
A control device includes a processor configured to copy a part of data stored in a first volume to a second volume, copy whole data stored in the first volume to a destination volume, and receive a request to read first data stored in the second volume. The processor is configured to read the first data from the second volume when the first data has been partially copied to the second volume. The processor is configured to read, when the first data has not been partially copied to the second volume, the first data from the first volume on basis of association information associating the first volume with the second volume. The processor is configured to identify, upon failing to read the first data from the first volume, the equivalent volume on basis of recovery information related to the destination volume as an equivalent volume of the first volume.