Restoring Hyper-V Virtual Machines

Overview

When you back up a Hyper-V VM, BackupEngine creates a manifest file that records the VM configuration, virtual disks, and chunk references. On restore, the agent reassembles the virtual disks from chunks and generates PowerShell commands to re-attach them to Hyper-V.

You can restore to the original host, a different Hyper-V host, or a new location on the same host.

Understanding the VM Restore Workflow

The restore process has these main steps:

• •1. Select the backup: On the Restore tab, find the Hyper-V backup set and select which destination's copy to restore from.
• •2. VM checklist: Verify the VM name, disks, and disk sizes. The manifest shows what will be restored.
• •3. Choose target folder: Specify where to reassemble the virtual disks (e.g., C:\HyperV\VMs\vm-name\).
• •4. Reassemble disks: BackupEngine downloads chunks from the backup storage (cloud or local) and reconstructs each VHD file.
• •5. Generate restore commands: The agent creates RESTORE_INFO.txt with PowerShell snippets to re-attach the disks and re-start the VM.
• •6. Manual re-attach: You run the PowerShell commands to create the VM in Hyper-V and start it.

Step-by-Step: Restoring a VM

• •1. Click the Restore tab in the desktop agent.
• •2. Find your Hyper-V backup set in the list. If multiple destinations exist, choose which copy to restore from (cloud or local).
• •3. The VM checklist appears: review the VM name, number of disks, and total size. If correct, proceed.
• •4. Click 'Choose Restore Location' and select or create a target folder (e.g., D:\VMs\production-web-01\).
• •5. Click 'Restore' to begin downloading and reassembling disks.
• •6. Restore progress shows per-disk status. Once all disks are reassembled, a RESTORE_INFO.txt file is created in the target folder.
• •7. Open RESTORE_INFO.txt and review the PowerShell commands. Copy the 'New-VM' and 'Add-VMHardDiskDrive' commands.
• •8. Open PowerShell as Administrator on the Hyper-V host and paste the commands to create and configure the VM.
• •9. Start the VM with 'Start-VM -Name vm-name' and verify it boots correctly.

The RESTORE_INFO.txt File

After reassembly completes, a RESTORE_INFO.txt file is written to the restore folder. It contains all the information needed to re-attach the VM.

# Hyper-V VM Restore Information
# Backup Date: 2026-04-22T10:30:00Z
# VM Name: production-web-01
# Disks: 3 (C:, D:, E:)
# Total Size: 120 GB

# Step 1: Create the VM
New-VM -Name production-web-01 \
  -MemoryStartupBytes 8GB \
  -SwitchName "Default Switch"

# Step 2: Add virtual disks
Add-VMHardDiskDrive -VMName production-web-01 \
  -Path "C:\VMs\production-web-01\disk-c.vhdx" \
  -ControllerType SCSI -ControllerNumber 0

Add-VMHardDiskDrive -VMName production-web-01 \
  -Path "C:\VMs\production-web-01\disk-d.vhdx" \
  -ControllerType SCSI -ControllerNumber 0

# Step 3: Start the VM
Start-VM -Name production-web-01

Verification and Troubleshooting

• •Verify chunk integrity: Each chunk is verified against its SHA-256 hash during reassembly. If a hash mismatch occurs, the backup storage is checked for bit-rot or tampering.
• •Disk space: Ensure the target folder has enough space for all disks (shown in the checklist).
• •Permissions: You need write access to the target folder. If using a network share, ensure it is mounted with sufficient permissions.
• •Hyper-V path: The VHDX files can be stored on any volume, including a different storage pool or SAN, as long as the Hyper-V host can access the path.
• •Network issues: If reassembly pauses due to network timeout, click 'Resume' to continue downloading from the last checkpoint.

Restoring to a Different Host

You can restore VM backups to a different Hyper-V host. The process is identical, except you run the PowerShell commands on the new host instead of the original.

• •The restored VM gets a new UUID automatically when you create it on the new host.
• •The guest OS (Windows Server, Linux, etc.) typically requires network reconfiguration or a full OS re-initialization on new hardware.
• •For dissimilar hardware (e.g., different RAID controllers or NIC cards), Windows may need driver injection during startup.
• •Once the guest OS boots, you may need to activate Windows or update NIC drivers.

Restoring Individual Disks

If you only need one disk from the VM backup (e.g., just the C: drive), you do not have to restore all disks.

• •On the VM checklist screen, toggle off the disks you do not want to restore.
• •Only the selected disks will be reassembled.
• •The RESTORE_INFO.txt will include Add-VMHardDiskDrive commands only for the disks you selected.