Hypervisor iSCSI Adapter Emulation for VM Migration

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Solution Overview

Problem

Traditional virtualization architectures do not support seamless live migration of virtual machines between information handling systems that utilize different iSCSI implementations, such as from a 'software initiator' to an iSCSI offload host bus adapter.

Innovation Solution

A method where the hypervisor instantiates a virtual machine with an initiator client, determines the storage interface type, and executes either an adapter driver for offload host bus adapters or an emulator for other adapters to facilitate input/output communications, enabling migration between different iSCSI implementations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional virtualization architectures are used, then hardware resource utilization is improved, but seamless live migration between different iSCSI implementations is not supported

Engineering Contradiction:

Improvemigration capabilityVSAvoidsystem availability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The hypervisor acts as an intermediary layer between the virtual machine and the storage array, abstracting the storage interface details. It detects the type of iSCSI implementation (software initiator or offload host bus adapter) and selects the appropriate driver or emulator to communicate with the storage array, enabling seamless migration between different implementations without affecting the virtual machine.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The hypervisor is designed to support multiple iSCSI implementations universally. It can interface with both software initiator and offload host bus adapter implementations, and even emulate the behavior of offload adapters when needed. This multi-functionality allows the system to maintain compatibility across different storage interface types while enabling live migration.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Productivity

If iSCSI offload host bus adapter is used, then storage I/O performance is improved, but compatibility with software initiator implementations is reduced

Engineering Contradiction:

Improvestorage I/O performanceVSAvoidimplementation compatibility

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

When an offload host bus adapter is detected, the hypervisor uses a specialized adapter driver to optimize storage I/O performance. When a software initiator is detected, it uses a software-based communication path. This intermediary layer ensures that performance optimizations are applied only when hardware offload is available, while maintaining compatibility with software-based implementations.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically changes its operational parameters based on the detected iSCSI implementation type. It adjusts the communication mechanism, driver selection, and emulation behavior according to whether the environment supports hardware offload or requires software initiation, thereby maintaining both performance and compatibility.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If virtual machine migration is enabled, then system flexibility is improved, but complexity of managing different adapters increases

Engineering Contradiction:

Improvesystem flexibilityVSAvoidadapter management complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The hypervisor centralizes the complexity of adapter management as an intermediary layer. It handles driver selection, emulation, and communication protocol adaptation automatically based on the detected implementation type. This abstracts the complexity from the virtual machine and migration process, maintaining system flexibility while managing complexity centrally.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The hypervisor performs self-detection and self-configuration when a virtual machine migrates to a different host. It automatically identifies the iSCSI implementation type, selects the appropriate driver or emulator, and configures the storage interface without manual intervention. This self-service capability maintains flexibility while reducing operational complexity.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS8990800B2System and method for increased system availability to network storage in virtualized environments

Publication Date: 2015.03.24 DELL PROD LP

AI summary

A method may include a hypervisor instantiating a virtual machine including an initiator client and the hypervisor determining whether a virtualized information handling system is interfaced to an associated storage resource via an offload host bus adapter (HBA). If the virtualized information handling system is interfaced to the associated storage resource via an offload HBA, the hypervisor may execute an adapter driver for the HBA, the adapter driver for communicating input/output communications between the virtual machine and the associated storage resource via the offload HBA. If the virtualized information handling system is interfaced to the associated storage resource via another adapter other than an offload HBA, the hypervisor may execute an emulator, the emulator for emulating the functionality of the adapter driver for the HBA and for communicating input/output communications between the virtual machine and the associated storage resource via the other adapter.