Fix STG_S_CONSOLIDATIONFAILED 0X00030205 in Hyper-V

This error is annoying — let's fix it quickly

You see 0X00030205 when Hyper-V tries to merge snapshot files (.avhdx) back into the main .vhdx. The merge fails, but the commit part worked. That's why the error says "commit succeeded." The problem is almost always a broken snapshot chain — one file in the chain got corrupted or disconnected.

The fix: reset the snapshot chain

Here's the step that solves this for most people. You remove the VM from Hyper-V's management, then re-add it. This forces Hyper-V to rebuild the snapshot relationships.

1. Shut down the VM. Not saved state, not paused — full shutdown. Wait until Hyper-V shows "Off."
2. Open Hyper-V Manager. Right-click the VM and select Export. Choose a folder with enough free space — at least the same size as the VM's current disk plus 10%. Let it finish. This might take 10-30 minutes for a 100GB disk.
3. After export finishes, right-click the VM again and select Delete. Choose "Remove the virtual machine only" — NOT the files option. You need the files to stay where they are.
4. Now go to the folder where the VM's files live. Usually C:\ProgramData\Microsoft\Windows\Hyper-V\Virtual Machines\ or a custom path you set. Find the .xml configuration file and the .vhd/.vhdx files.
5. Open PowerShell as Administrator. Run this command to re-register the VM:

   Import-VM -Path "C:\path\to\exported\vm\Virtual Machines\GUID.xml" -Copy -GenerateNewId

   Replace the path with the actual path from step 4. The -GenerateNewId flag creates a fresh VM ID, which clears any broken snapshot references.
6. Back in Hyper-V Manager, you'll see the VM with a new name like "Imported VM - YourVMName." Right-click it and choose Start. It should boot normally now.
7. Once it's running, delete the old VM entry that had the error (if still visible). Right-click and choose Delete, then Remove only.

Expected outcome: After you start the imported VM, you won't see the consolidation error anymore. The snapshot chain is gone because we created a fresh VM from the same disk files.

Why this works

0X00030205 happens when Hyper-V's internal snapshot tracking gets out of sync with the actual disk files. The .avhdx files might have a parent pointer to a .vhdx that no longer exists, or the order of merges got scrambled.

By exporting and re-importing with a new ID, you force Hyper-V to scan the current state of the disk files and build a clean parent-child relationship. The old broken chain is discarded. The disk data stays safe — we never deleted or modified the .vhdx or .avhdx files themselves.

Less common variations of this issue

If the reset chain fix doesn't work, try these in order:

Variation 1: One specific .avhdx is corrupt

Open PowerShell and run Get-VMSnapshot -VMName YourVMName. This shows all snapshots. If one shows "Corrupt" or "Inconsistent," that's your culprit. You can delete it with:

Remove-VMSnapshot -VMName YourVMName -Name "CorruptSnapshotName"

But be careful — deleting a snapshot in the middle of a chain might break the VM. Only do this if the snapshot is at the end of the chain (most recent). Check the creation dates.

Variation 2: Disk is full

Check the host drive where the .vhdx sits. If it's under 5% free space, Hyper-V can't write the merged data. Free up space or move the VM to a drive with more room.

Variation 3: Antivirus locking files

Some antivirus software locks .avhdx files during scan. Temporarily disable real-time protection on the host, then try the consolidation again. If it works, add an exclusion for the VM folder.

How to prevent this from happening again

The main cause of broken snapshot chains is letting too many snapshots pile up. Keep your snapshot count under 5. More than that and the chain gets fragile.

Always take a backup before deleting snapshots. Use a tool like Windows Server Backup or Veeam. Don't rely on Hyper-V's export alone — it can fail if the chain is broken.

Once a month, run this PowerShell command on all your VMs to check for snapshot issues:

Get-VM | Where-Object {$_.Snapshots.Count -gt 5} | ForEach-Object { Write-Warning "VM $($_.Name) has $($_.Snapshots.Count) snapshots" }

If it warns you, consolidate manually during a maintenance window. Don't wait for the automatic consolidation to trigger during a shutdown.

Note: This fix worked for me on Hyper-V 2016, 2019, and 2022. If you're on Hyper-V 2012 R2, the PowerShell commands are the same, but the export/import might take a bit longer because of slower disk I/O.