Consistent LUN Binding Across Clustered Nodes

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional server cluster implementations fail to enforce consistent inter-node binding of shared storage resources, leading to variability in how nodes access and manage shared storage resources.

Innovation Solution

A system and method for consistently binding shared storage resources across nodes in a multi-node cluster, utilizing a computer program product with instructions for determining and assigning binding labels, ensuring that all nodes use the same label for a logical unit number (LUN) in a storage enclosure, and detecting universally unique identifiers (UUIDs) to manage binding, thereby ensuring consistent access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional server cluster implementations allow nodes to bind shared storage resources independently, then each node can access storage resources flexibly, but binding consistency across nodes deteriorates

Engineering Contradiction:

Improveflexibility in storage accessVSAvoidbinding consistency

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The system performs preliminary actions by detecting UUIDs of shared storage resources before binding operations and establishing a binding consistency policy in advance. This allows the cluster to pre-determine binding labels and paths for all nodes, ensuring that when binding occurs, consistency is already predetermined rather than negotiated during actual storage access operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms where nodes continuously monitor and detect binding operations performed by other nodes on shared storage resources. When a node detects that another node has bound a storage resource with a different label or path, it can report this inconsistency to the cluster management system, which then enforces policy compliance by standardizing the binding across all nodes.

Inventive Principle:

Principle #23Feedback

2Adaptability or versatility

If binding labels are assigned dynamically without coordination, then nodes can adapt to storage resources independently, but management complexity increases

Engineering Contradiction:

Improveindependent node adaptationVSAvoidmanagement complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system creates a universal binding policy that serves multiple functions: it assigns binding labels, establishes access paths, ensures consistency across nodes, and simplifies management all through a single coordinated mechanism. This universal approach replaces multiple independent binding operations with one standardized process that handles all binding needs for the cluster.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system introduces an intermediary binding consistency policy that mediates between individual node binding operations. This intermediary layer coordinates binding label assignment across all nodes, preventing direct conflicts while maintaining centralized management control, thus reducing overall system complexity despite the need for coordinated binding.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If nodes access shared storage in different orders, then concurrent access flexibility is maintained, but binding variability increases

Engineering Contradiction:

Improveconcurrent access capabilityVSAvoidbinding uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system uses asymmetric binding label assignment where the first node to detect and bind a shared storage resource receives a predetermined binding label, while subsequent nodes are forced to use the same label regardless of their access order. This asymmetric approach maintains concurrent access flexibility while ensuring binding uniformity by design rather than by chance.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The system changes the binding parameter from dynamic (allowing each node to choose its own label based on access order) to static (enforcing a predetermined label for all nodes). This parameter change ensures that regardless of the order in which nodes access shared storage, the binding label remains constant across all nodes, achieving both concurrent access and binding uniformity.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9807052B2Consistent binding of shared storage across clustered servers

Publication Date: 2017.10.31 DELL PROD LP

AI summary

An information handling system includes first and second nodes and a storage enclosure. The nodes share access to the storage enclosure. The nodes bind a logical unit number (LUN) in the storage enclosure consistently regardless of an order in which the two devices access the LUN. The system further preferably includes a switch between the nodes and the storage enclosure wherein multiple paths exist between a node and the storage enclosure. The storage enclosure preferably includes first and second storage processors and multiple ports per processor. The first node preferably includes first and second host bus adapters. The first host bus adapter preferably connects the node to a first of the switches and the second host bus adapter connects the node to a second of the switches. The system preferably includes multiple paths between the first node and a LUN in the storage enclosure.