Remote Copy Synchronization via Syncio Bitmap Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In storage system environments, the synchronization of data during remote copy operations is hindered by contention between syncio processes and traditional remote copy mechanisms, particularly due to the prolonged reservation of tracks by syncio processes, which disrupts timely synchronization of volumes between primary and secondary storage controllers.
Innovation Solution
The implementation of a syncio OOS bitmap and syncio CR bitmap, in addition to standard OOS and CR bitmaps, allows for the identification and management of tracks reserved by the syncio process, enabling synchronization operations to proceed without interruption and integrating syncio processes into existing mechanisms without impacting performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If syncio processes reserve tracks for prolonged periods to complete write operations, then write completion reliability is improved, but remote copy synchronization speed deteriorates due to contention with syncio processes
Solution Approach 1:
The patent segments the track reservation management by creating separate bitmap data structures: a first bitmap for standard remote copy operations and a second bitmap for syncio process reservations. This segmentation allows independent tracking and management of tracks reserved by syncio processes versus those reserved for remote copy operations, enabling the system to identify and prioritize critical synchronization tracks without being blocked by prolonged syncio reservations.
Solution Approach 2:
The patent introduces an intermediary mechanism in the form of a syncio bitmap that acts as a mediator between syncio processes and the remote copy synchronization system. This intermediary bitmap tracks which tracks are reserved by syncio processes, allowing the remote copy mechanism to make informed decisions about which tracks to prioritize for copying, thereby reducing direct contention while maintaining syncio write completion reliability.
2Device complexity
If a single bitmap is used to track all tracks requiring copy operations, then data structure simplicity is maintained, but synchronization performance deteriorates due to contention between syncio processes and remote copy operations
Solution Approach 1:
The patent divides the single bitmap into multiple specialized bitmaps: a first bitmap structure for tracking tracks requiring copy operations in standard remote copy scenarios, and a second bitmap structure specifically for tracking tracks reserved by syncio processes. This segmentation resolves contention by enabling independent management and processing of different track types, improving synchronization performance while maintaining reasonable data structure complexity through modular design.
Solution Approach 2:
The patent creates a universal bitmap management system where multiple bitmap structures serve different functions but work together within a unified remote copy framework. The first bitmap handles standard remote copy tracking while the second bitmap handles syncio reservation tracking, and both are integrated into the same remote copy process to provide comprehensive track management across different operation types.
Data Source
AI summary
A synchronization of data is performed via remote copy operations from a primary storage controller to a secondary storage controller, wherein input/output (I/O) requests are received at the primary storage controller from a host both via a bus interface and a network interface while the remote copy operations are in progress. A first data structure stores identification of tracks written via the network interface that are to be copied from the primary storage controller to the secondary storage controller for the synchronization of data. A second data structure stores identification of tracks written via the bus interface that are to be copied from the primary storage controller to the secondary storage controller for the synchronization of data.