VHDX Streaming via Snapshot and GUID Update

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Solution Overview

Problem

The existing process of creating a shared virtual disk for streaming in virtual machines is time-consuming and requires repeated disk cloning, especially with significant updates to the operating system.

Innovation Solution

Converting a snapshot or image of a virtual hard disk file into a streaming capable VHDX file, which allows a provisioning services server to stream the VHDX file over a virtual network established by the hypervisor, without using disk cloning, by creating a read-only VHDX file and updating its partition GUIDs, modifying the registry for earlier network subsystem booting, and changing the local disk to a non-boot disk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If disk cloning is used to create a shared virtual disk for streaming, then the virtual disk can be established for streaming purposes, but the process is time-consuming and must be repeated for significant OS updates

Engineering Contradiction:

Improveshared virtual disk creation speedVSAvoidtime for disk cloning and fixup process

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The patent uses snapshot technology to create a copy-on-write replica of the virtual hard disk file. Instead of cloning the entire disk, a snapshot captures the state at a point in time, allowing rapid creation of streaming-capable virtual disks without time-consuming copy operations

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent modifies partition GUIDs (Globally Unique Identifiers) to differentiate the snapshot from the parent disk. This parameter change enables the snapshot to be recognized as a distinct bootable entity while maintaining the underlying storage efficiency of snapshot technology

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If multiple virtual machines are streamed from the same shared virtual disk, then storage requirements are reduced, but boot storms may occur affecting system stability

Engineering Contradiction:

Improvehypervisor storage requirementsVSAvoidsystem stability during boot

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent segments the boot process by modifying the registry to update network subsystem ordering, ensuring network initialization occurs earlier in the boot sequence. This segmentation prevents boot storms by coordinating the boot process across multiple virtual machines streaming from the same disk

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary modifications to the virtual disk's registry and boot configuration before streaming to multiple VMs. By pre-configuring the network subsystem ordering and boot parameters, the system prevents boot storms before they occur, ensuring stable multi-VM streaming

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11238015B2Instant hyper-v streaming

Publication Date: 2022.02.01 CITRIX SYSTEMS INC

AI summary

Described embodiments provide systems and methods for streaming a virtual disk. A first virtual hard disk (VHDX) file can be converted into a read-only VHDX file on a hypervisor. A second VHDX file can be created as a snapshot of the read-only VHDX file on the hypervisor. Partition globally unique identifiers (GUIDs) of the second VHDX file can be updated to be different from those of the read-only VHDX file. A provisioning services server executing on the hypervisor can stream the second VHDX file as a virtual disk over a virtual network established by the hypervisor, by booting the second VHDX file over the virtual network.