Active-Active Storage Registration Replication via Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing data storage systems face challenges in efficiently managing and replicating registration and reservation state information across multiple data storage systems, particularly in active-active configurations, where hosts need to access and manage logical devices spanning multiple physical devices without direct access to individual storage units.
Innovation Solution
A method and system for processing commands that determine whether registration and reservation state information modifications need to be replicated across multiple data storage systems, executing appropriate updates on each system, and handling commands such as creating, releasing, or preempting reservations, while maintaining a unified logical device view for hosts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If registration and reservation state information is replicated across multiple data storage systems in an active-active configuration, then system reliability and accessibility are improved, but device complexity and information synchronization overhead increase
Solution Approach 1:
The patent segments the data storage system into multiple independent data storage systems (first data storage system, second data storage system), each maintaining its own registration and reservation state information in separate data containers. This segmentation allows each system to operate independently while maintaining synchronized state information, improving reliability without requiring a single complex centralized system.
Solution Approach 2:
The patent implements copying of registration and reservation state information between data storage systems through command replication. When a command modifies state information on one system, the same command is replicated to the other system, ensuring both systems maintain identical copies of the state information. This copying mechanism improves reliability by providing redundant state information across multiple systems.
2Adaptability or versatility
If registration and reservation state information is replicated across multiple data storage systems, then data accessibility and failover capability are improved, but information synchronization overhead and processing time increase
Solution Approach 1:
The patent performs preliminary actions by maintaining registration and reservation state information in data containers on both data storage systems in advance. When failover is needed, the target system already has the necessary state information ready, eliminating the need for time-consuming synchronization during the failover event. Commands are replicated and executed on both systems proactively to ensure state information is prepared beforehand.
3Productivity
If multiple data storage systems maintain independent registration and reservation state information, then system independence and operational flexibility are improved, but data consistency and unified logical device view deteriorate
Solution Approach 1:
The patent implements feedback through command replication and execution. When a command is executed on one data storage system that modifies registration or reservation state information, the same command is replicated to the other system, which executes it and returns a status. This feedback mechanism ensures both systems maintain consistent state information, preserving data consistency while allowing independent operation.
Solution Approach 2:
The patent merges the registration and reservation state information from multiple data storage systems into a unified logical device view for hosts. Although each data storage system maintains independent data containers, the systems work together to present a single logical device to hosts, combining their capabilities while maintaining data consistency through command replication.
Data Source
AI summary
Described are techniques for maintaining and using registration and reservation information in an active-active configuration that provides automated data replication of a logical device. Various commands may be issued from one or more hosts to read and modify registration and reservation information in the active-active configuration. Processing is performed to service the various commands and provide a host or client with a consolidated logical view of a data storage system including the logical device where the host is allowed to issue I/Os over multiple paths to the logical device. Depending on the command, such processing may include replicating or mirroring reservation state information between two data storage systems each including a different device configured as the logical device.