avhdx

.avhdx — Azure Virtual Hard Disk v2

Microsoft · 2013

Developer
Microsoft
Category
Disk Images
MIME Type
application/vnd.ms.vhd
First Released
2013
Open Format
No
File Signature
Not a standard file signature, but recognized by its file structure and metadata within virtualization software.
At a Glance
.avhdx
Azure Virtual Hard Disk v2

AVHDX is a virtual hard disk file format used by Microsoft for cloud and virtualization environments.

Reviewed on July 17, 2026
Compression
Varies (Can be compressed during backup/snapshot, base format is not inherently compressed)
Transparency
No
Editability
Medium (Requires specific virtualization software)
Best for
Virtual Machine Storage

Key Features

  • Supports virtual disks up to 16 TB.
  • Improved performance over VHD format.
  • Enhanced reliability and resilience against corruption.
  • Optimized for cloud and virtualization platforms like Azure and Hyper-V.

Best For

  • Running virtual machines on Microsoft Azure.
  • Environments heavily reliant on Microsoft Hyper-V.
  • Storing large virtual disks for performance-intensive applications.
  • Scenarios requiring robust and reliable virtual disk storage.

Less Ideal For

  • Cross-platform compatibility with non-Microsoft virtualization solutions.
  • Archiving or compressing large data sets outside of virtualization.
  • Web-based applications requiring simple file sharing.
  • Mobile device storage or application data.

Common Use Cases

  • Storing virtual machine operating systems and data in Azure.
  • Creating and managing virtual hard disks for Hyper-V environments.
  • Enabling snapshotting and differential disk operations for VMs.
  • Migrating physical servers to virtual machines.

How to Open It

  1. Open with Hyper-V Manager by creating a new virtual machine or attaching to an existing one.
  2. Use PowerShell cmdlets like `Mount-VHD` for mounting.
  3. Convert to VHD or VHDX formats using tools like StarWind V2V Converter or QEMU.
  4. Access data within the disk image using disk management tools within a running VM.

What is a .avhdx file?

AVHDX is a disk image file format primarily used by Microsoft Azure and Hyper-V for storing virtual machine disks. It's an evolution of the older VHD format, offering improved performance, reliability, and support for larger disk sizes. AVHDX files are designed to efficiently store the data of a virtual hard drive, allowing for dynamic expansion and snapshots. This format is crucial for cloud computing environments where virtual machines need robust and scalable storage solutions.

Programs That Open .avhdx Files

PlatformProgram
WindowsMicrosoft Hyper-V ManagerFreeOfficial
Microsoft Virtual Machine ManagerPaidOfficial
StarWind V2V ConverterFree
macOSQEMUFree
LinuxQEMUFree
virt-managerFree

How to Convert .avhdx Files

FormatMethod
.VHDStarWind V2V Converter, QEMU
.VHDXHyper-V Manager, PowerShell
.VMDKStarWind V2V Converter, QEMU

Common Problems with .avhdx Files

⚠️ Cannot open AVHDX file directly on a standard desktop OS.
AVHDX files are virtual disk images and require virtualization software like Hyper-V or QEMU to be mounted or used.
⚠️ Performance issues when not using native Microsoft virtualization.
Ensure compatibility and consider conversion to a more universally supported format like VMDK or QCOW2 if using non-Microsoft hypervisors.

Frequently Asked Questions

What is the difference between VHD and AVHDX?▼

AVHDX is an updated format that supports larger disk sizes (up to 16TB), offers better performance, and increased reliability compared to the older VHD format.

Can AVHDX files be used on macOS or Linux?▼

Directly, no. However, tools like QEMU can be used on macOS and Linux to work with AVHDX files, though performance and compatibility may vary.

How do I backup an AVHDX file?▼

Backup AVHDX files using Hyper-V's built-in backup features, system center, or by creating a copy of the file while the virtual machine is shut down or in a saved state.

Technical Details

AVHDX is a proprietary binary format developed by Microsoft. It is an update to the VHD format and supports disk sizes up to 16 TB, with a more resilient metadata structure to prevent corruption during unexpected shutdowns. It also offers better performance due to its block-based structure and optimized I/O operations.

Did You Know?

AVHDX is the default disk format for Azure virtual machines.
The 'AV' in AVHDX stands for Azure Virtual, indicating its cloud origins.

Security Information

AVHDX files themselves do not inherently contain malware, but they can hold operating systems and sensitive data. Treat them with the same security precautions as any storage medium, ensuring they are only opened with trusted virtualization software and from reputable sources.