Hypervisor-Agnostic VM Network Reconfiguration via Directive Files

Solution Overview

Problem

Existing disaster recovery techniques for virtual machines lack a standardized, hypervisor-agnostic method for network reconfiguration during migration to remote sites, often requiring guest credentials or hypervisor access, which is not scalable and secure.

Innovation Solution

The implementation of a hypervisor-agnostic network reconfiguration method that uses a network configuration directive file to reconfigure the virtual machine's network settings after migration, either by mounting the guest file system using tools like 'guestfish' or employing a helper virtual machine with an RPC service, allowing the virtual machine to access and apply new network settings without requiring guest credentials or hypervisor access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If legacy approaches use hypervisor backdoor or manual reconfiguration, then network reconfiguration can be achieved, but security is compromised and scalability is poor

Engineering Contradiction:

Improvenetwork reconfiguration capabilityVSAvoidsecurity risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary file (e.g., /run/flavor.netcfg) that acts as a mediator between the migration system and the guest VM. This file contains network configuration directives that the guest VM automatically applies, eliminating the need for direct hypervisor backdoor access or manual reconfiguration. The intermediary file approach maintains security by avoiding credential exposure while achieving reliable network reconfiguration.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The guest VM is equipped with automated mechanisms (such as inotify watchers or startup scripts) that automatically detect and apply network configuration directives from the intermediary file. This self-service capability eliminates the need for external manual intervention or hypervisor access, improving both security and scalability while maintaining reliable network reconfiguration.

Inventive Principle:

Principle #25Self-service

2Reliability

If manual reconfiguration is used for each virtual machine migration, then network settings can be updated, but the process does not scale with increased virtual machine numbers and migration frequency

Engineering Contradiction:

Improvenetwork configuration accuracyVSAvoidmigration scalability

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system implements automated network reconfiguration within the guest VM through mechanisms such as inotify watchers that monitor for configuration files, startup scripts that automatically apply network settings, or systemd services that handle network configuration. This automation eliminates manual intervention, ensuring accurate network configuration while enabling the system to scale to handle increased numbers of virtual machines and migration frequency.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The network configuration directives are prepared in advance and stored in an intermediary file before the guest VM needs to apply them. This preliminary preparation of configuration data allows the guest VM to quickly and accurately apply network settings during migration without manual intervention, improving both configuration accuracy and migration scalability.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If guest credentials or hypervisor access are required for network reconfiguration, then network settings can be changed, but the complexity of the process increases

Engineering Contradiction:

Improvenetwork reconfiguration capabilityVSAvoidreconfiguration process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary file (e.g., /run/flavor.netcfg) that acts as a mediator between the migration system and the guest VM. This file contains network configuration directives that the guest VM automatically applies, eliminating the need for direct hypervisor backdoor access or manual reconfiguration. The intermediary file approach maintains security by avoiding credential exposure while achieving reliable network reconfiguration.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The guest VM is equipped with automated mechanisms (such as inotify watchers or startup scripts) that automatically detect and apply network configuration directives from the intermediary file. This self-service capability eliminates the need for external manual intervention or hypervisor access, improving both security and scalability while maintaining reliable network reconfiguration.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS11074096B2Network reconfiguration in hypervisor-agnostic disaster recovery scenarios

Publication Date: 2021.07.27 NUTANIX INC

AI summary

Systems for restarting a virtual machine in a disaster recovery scenario where a network configuration differs between the failed system and the recovery system. A method commences upon identifying a disaster recovery plan for restarting a virtual machine from a first system on a second system (e.g., a recovery system). A configuration for providing network access at the second system through an adapter present in the second system is stored at a location accessible to the second system. Restarting the virtual machine at the second system upon detection of a failure event at the first system.