Managing Orphaned .avhdx Files in Hyper-V with PowerShell

Question

I'm managing a Hyper-V environment and looking to clean up my hard drive to free up space. Specifically, I want to delete orphaned .avhdx files and possibly move some to external storage. I prefer using cmd/batch and/or PowerShell for this task.

So far, I've tried using PowerShell to correlate .avhdx files with the list of VMs and checkpoints in the Hyper-V Manager GUI. However, I'm facing challenges in accurately identifying which .avhdx files are orphaned and can be safely deleted or moved.

Here's what I've tried:

1. Using Get-VM and Get-VHD cmdlets to list VHDX files associated with VMs.
2. Matching these files against all .vhdx and .avhdx files on the disk using Get-ChildItem.

Despite these efforts, I'm not confident in the accuracy of the results, especially in determining the linkage between .avhdx files and specific VMs or checkpoints.

I'm seeking advice on:

• Effective methods to identify orphaned .avhdx files using PowerShell or cmd.
• Best practices for managing these files in a Hyper-V environment.
• Any scripts or tools that can facilitate this process.

Any insights or recommendations would be greatly appreciated!

P.S. I have also posted the question here on r/HyperV subreddit.

Answer 1

I've come up with a PowerShell solution. This script will help identify which .avhdx files in the Hyper-V environment are orphaned, meaning any VM snapshots are not currently used. Here's how it works:

# Get the list of AVHDX files used by the VM snapshots $snapshotVHDs = Get-VM | Get-VMSnapshot | ForEach-Object { $snapshotName = $_.Name $_ | Select-Object -ExpandProperty HardDrives | ForEach-Object { Get-VHD $_.Path | Where-Object { $_.Path -like "*.avhdx" } | Select-Object -Property Path } } | Select-Object -ExpandProperty Path -Unique # Get all AVHDX files in the specified directory $allVHDs = Get-ChildItem -Path "C:\Users\Public\Documents\Hyper-V\Virtual hard disks" -Filter *.avhdx -Recurse | Select-Object -ExpandProperty FullName # Compare the lists to find orphaned AVHDX files $orphanedVHDs = $allVHDs | Where-Object { $_ -notin $snapshotVHDs } # Output the orphaned files $orphanedVHDs | ForEach-Object { Write-Host "Orphaned File: $_" } 

How it Works:

1. Snapshot VHDs Collection: The script first collects the paths of all .avhdx files that are currently in use by VM snapshots.

2. Directory Scan for AVHDX Files: It then scans the specified directory (C:\Users\Public\Documents\Hyper-V\Virtual hard disks) for all .avhdx files.

3. Identifying Orphaned Files: By comparing these two sets of files, the script determines which .avhdx files in the directory are not currently used by any snapshots. These are your orphaned files.

4. Results: Finally, it outputs the paths of these orphaned .avhdx files.

This script should help safely identify orphaned .avhdx files that can then be considered deleted or archived, depending on the cleanup strategy. However, as a precaution, always ensure that these files are indeed not required by any VMs before proceeding with deletion to avoid any accidental data loss.