VHDX Support

Bug Reference

CLOUDSTACK-6288

Branch

4.4, master

Introduction

As enterprise workloads for virtual environments grow in size and in performance demands, virtual hard disk (VHD) formats need to accommodate them. Hyper-V in Windows Server 2012 introduces a new version of the VHD format called VHDX, which is designed to handle current and future workloads. VHDX has a much larger storage capacity than the older VHD format. It also provides data corruption protection during power failures and optimizes structural alignments of dynamic and differencing disks to prevent performance degradation on new, large-sector physical disks.

Currently in cloudstack, only VHD virtual disk format is supported for Hyper-V. With this feature support for VHDX format will also be enabled for Hyper-V.

Purpose

This is a feature specification for supporting VHDX image format for Hyper-V.

References

• Hyper-V Virtual Hard Disk Format Overview
• Why use VHDX?

Document History

Glossary

Instance/vm - Virtual machine running on a hypervisor. The terms may be used interchangeably.

Feature Specifications

• A vhdx (as well as vhd) template can now be registered.
• An instance can be created on hyperv with a vhdx (as well as vhd) template.
• All migration, download volume, create template operation should work against vhdx and vhd.
• From 4.4 onwards data disks will be created of type vhdx. In 4.3 they were of vhd format.
• All operations (migration, download volume, create template from volume) will continue to work (on vhd volumes) for anyone who upgrades from 4.3 to 4.4.

Test Guidelines

Functional

Negative

Support-ability Characteristics

Logs can be looked up at the following location

• The Hyper-V agent logs can be seen in windows event viewer on the respective hosts. The logs can be filtered by source "CloudStack Hyper-V Agent".

Configuration Characteristics

Users Communities

Supported Hypervisor

This feature is implemented for Windows Server 2012 R2 and Hyper-V 2012 R2 (Core).

Use cases

Architecture and Design description

Database modifications

There are no database schema changes for this feature.

Web Services APIs

UI flow

IP Clearance

No IP dependencies are introduced by this feature.

Appendix

Appendix A:

Appendix B: