VHD (Virtual Hard Disk) is a file format that allows virtual hard drives to be stored and transferred. VHD files are commonly used with virtualization platforms like Microsoft Hyper-V and VMware to act as virtual drives for virtual machines.
There may be situations where you need to restore or migrate a VHD back to a physical disk. For example, if a physical server crashes, the VHD backup can be used to restore the disk contents to new hardware. Similarly, when migrating from a virtual environment back to physical, VHD restoration can prove useful.
This article will provide a step-by-step guide on how to properly restore a VHD file to a physical disk on Windows. We will cover prerequisites, methods using native Windows tools as well as third-party solutions, troubleshooting tips, and best practices.
Before starting the VHD restoration process, make sure you have the following:
- VHD file that needs to be restored. This VHD should be a backup copy of the original physical disk.
- A compatible blank physical disk with sufficient storage to hold the VHD contents.
- Administrative access to the Windows machine where the restoration will take place.
- Latest version of Windows 10 or Windows Server installed. Older versions may lack native VHD support.
- Backup of existing data on the physical disk if it is not blank. The restoration process will wipe out any existing data.
- Microsoft Hyper-V feature enabled if wanting to use native Hyper-V tools.
- Software tools if wanting to use third-party solutions (e.g. StarWind V2V Converter).
VHD stands for Virtual Hard Disk. It is a file format containing the contents of a virtualized hard drive used in virtual machines.
There are 2 types of VHDs:
Fixed VHD – The VHD file is pre-allocated to the maximum storage size during creation. This provides better performance but less flexibility.
Dynamic VHD – The VHD file starts small and expands as data is added. This saves storage space while allowing on-demand growth.
VHDX is a newer version of VHD that supports larger storage sizes. But VHD remains commonly used and compatible across more virtualization platforms.
The key benefits of VHDs include:
- Portability – The VHD file is easy to move between host systems;
- Backup/Recovery – VHD makes backup and restoration of virtual drives convenient;
- Replication – New VMs can be easily created by replicating VHDs.
However, VHDs also have limitations like maximum file size (2040 GB), possible corruption, and performance overhead.
Preparation for Restoration
Before starting the VHD restoration, the target physical disk needs to be prepared:
- The physical disk must have unallocated space at least equal to the size of the VHD. Use Disk Management on Windows to delete existing partitions if needed.
- Create bootable installation media for your Windows version if the VHD contains the OS boot partition. This will be required to make the restored disk bootable.
- Attach the VHD in Hyper-V Manager and scan for errors. Use chkdsk or a VHD repair tool to fix any corruption issues detected.
- Make a backup copy of the VHD file before proceeding. Restore this backup if anything goes wrong with the original during the process.
There are several methods available to restore a VHD to a physical disk:
Using Native Windows Tools – Windows 10 and Windows Server include Hyper-V and Disk Management which allow VHD restoration via GUI and PowerShell.
Third-Party VHD Restore Software – Specialized tools like StarWind V2V Converter simplify the process with easy-to-use interfaces.
Manual Command-Line Utilities – For advanced users, diskpart and other CLI tools can directly copy VHD contents to a disk.
Step-by-Step Restoration with Windows Tools
Follow these steps to restore a VHD using native Windows features:
- Open Disk Management. Right-click on the blank physical disk and select Offline. This will disconnect it temporarily.
- Start Hyper-V Manager and click Connect under Actions. Browse and select the VHD file.
- The VHD will show up as a disk under Storage in Hyper-V. Right-click and choose Settings.
- Under Hardware, select IDE Controller > DVD Drive and check Enable. This will allow bootable media access later.
- Right-click the VHD again and select Connect. The VHD will now appear in Disk Management as an available disk.
- In Disk Management, right-click on the VHD and select Online. The disk will become accessible.
- Right-click on the blank physical disk and choose Convert to MBR disk. Select OK to confirm.
- Right-click the physical disk again and choose New Simple Volume. Go through the wizard to create a new partition utilizing the entire disk space.
- When complete, right-click on the volume and select Change Drive Letter and Paths. Assign the same drive letter as the VHD disk.
- With the two disks online with the same drive letters, copy all contents from the VHD volume to the physical disk.
- Detach the VHD in Hyper-V once the copy finishes. Right-click on the physical disk in Disk Management and select Online to reconnect it.
- To make the physical disk bootable, use the earlier created installation media to boot and repair the MBR using bootrec commands.
The VHD restoration to physical disk is now fully completed. Verify proper functioning before putting the system into production use.
Restoration Using Third-Party Tools
Third-party VHD restore software provides added convenience compared to native Windows tools:
DiskInternals VMFS Recovery – Does vhd file recovery and also allows you to convert VHD to physical disk with a simple GUI. Fully automates the restoration process.
Veeam Backup & Replication – Included with the paid Veeam backup product. Provides role-based restore of VHD to physical hardware.
Double-Take – VHD restore requires Double-Take’s paid migration module. Supports scheduled and automated VHD migration jobs.
Here are the basic steps to restore a VHD using StarWind V2V Converter:
- Select the source VHD file and target physical disk in StarWind.
- Choose the restoration options – volume layout, drive letter, partition style etc.
- StarWind will create a volume on the disk matching the VHD configuration.
- Click Convert to initiate the VHD to disk restoration process.
- Any boot partitions will need to be made bootable afterwards via bootable media.
- Conversion process is fully automated compared to native Windows tools.
Once the VHD restore finishes, follow these steps before using the physical disk:
- Check all partitions and data were restored properly without errors or corruption.
- Update drivers if needed for the new hardware environment (AHCI vs IDE etc).
- Modify boot configuration to set the restored disk as primary boot device in the BIOS.
- Reactivate OS or programs if required due to significant hardware changes.
- Delete the VHD file and detach it from Hyper-V if a temporary file was used.
The restored physical disk can now be used normally as needed. Monitor its health and performance for a few days to ensure stability.
Non-bootable restored disk
- Use installation media to rebuild the BCD via bootrec commands.
- Change BIOS settings from IDE to AHCI mode if OS installed in different mode.
VHD appears as unallocated space
- Assign a drive letter to the volume in Disk Management.
- Extend the volume to utilize available unallocated space.
Corrupted VHD file
- Use CHKDSK to check and repair VHD corruption issues.
- Restore from a backup VHD copy not affected by corruption.
Restored content mismatch
- The physical disk size might be inadequate for VHD contents. Expand disk capacity.
- Content might have changed between VHD backup and restoration. Restore from an earlier backup.
Errors converting VHD
- Third-party tools can sometimes fail with complex VHDs. Use native Windows commands for restoration.
If problems persist, seeking help from a professional system administrator is recommended.
Best Practices and Tips
- Regularly check VHDs for corruption and fix issues proactively;
- Make multiple backups of VHDs in case restoration is ever needed;
- Validate restoration with original disk contents before production use;
- Use Windows native tools for maximum control over the process;
- Script key restoration steps for automated execution without manual intervention;
- Document important volume and disk information like drive letters and partition layouts;
- Preserve the original disk as long as possible after restoration for recovery purposes.
Proper care and maintenance of the restored disk is required for long-term viability. Schedule regular backups and health monitoring.
Restoring a VHD to a physical disk can provide an important recovery capability in the event of disk failure or migration back from virtual machines. With the methods outlined in this guide, the process can be executed smoothly while avoiding potential pitfalls. Careful planning along with following best practices is key to successful VHD restoration. This enables maintaining business continuity and maximum uptime for critical systems.