Virtual Device Removal Prevention via Usage State Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In virtualized computer systems, existing virtualization managers struggle to safely remove virtual devices without disrupting VM execution, often preventing removal even when not in use, leading to resource wastage and potential data loss.

Innovation Solution

The virtualization manager determines the usage state of virtual devices using collected statistics and current use status, allowing safe removal without shutting down the VM by blocking removal requests if the device is in use and confirming with the user if necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the virtualization manager prevents removal of any virtual device when the VM is running, then data loss and VM failure are avoided, but resource wastage occurs and flexibility is reduced

Engineering Contradiction:

ImproveVM execution stabilityVSAvoidVirtual device management flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by making the removal policy device-specific rather than system-wide. The virtualization manager evaluates each virtual device individually to determine if it is currently in use, allowing removal decisions to be made on a per-device basis. This enables flexible management where some devices can be removed while the VM runs, while others remain protected, resolving the contradiction between reliability and adaptability.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If the virtualization manager allows removal of virtual devices while the VM is running, then resource flexibility is improved, but data loss and networking failures may occur

Engineering Contradiction:

ImproveVirtual device management flexibilityVSAvoidData loss and networking failures

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by checking the usage state of each virtual device before allowing removal. The virtualization manager proactively determines whether a device is currently in use by the VM before processing a removal request. This preliminary check prevents harmful removals that would cause data loss or networking failures while allowing safe removals, thus enabling flexible management without risking system stability.

Inventive Principle:

Principle #10Preliminary action

3Measurement precision

If usage statistics are collected continuously to determine device usage state, then accurate removal decisions are made, but system overhead increases

Engineering Contradiction:

ImproveDevice usage state detection accuracyVSAvoidComputational resources for monitoring

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by collecting usage statistics only when necessary to make removal decisions, rather than continuously monitoring all devices at all times. The virtualization manager retrieves usage state information on-demand when a removal request is received, balancing measurement precision with reduced system overhead. This approach provides accurate enough information for safe removal decisions without the excessive resource consumption of continuous monitoring.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS9817688B2Identifying and preventing removal of virtual hardware

Publication Date: 2017.11.14 RED HAT ISRAEL

AI summary

A virtualization manager receives a request to disconnect a virtual device associated with a virtual machine. The virtualization manager then determines a usage state of the virtual device in view of collected usage statistics for the virtual device. Responsive to determining that the determined usage state of the virtual device indicates that the virtual device is in use, the virtualization manager requests confirmation for disconnecting the virtual device from the virtual machine.