Powershell — Repair Vhdx

# Recreate the differencing disk from healthy parent $parentPath = "D:\BaseImages\parent.vhdx" $newChildPath = "E:\VMs\newchild.vhdx" New-VHD -ParentPath $parentPath -Path $newChildPath -Differencing Advanced Script: Auto-Repair with Backup Fallback <# .SYNOPSIS Attempts to repair a VHDX file, falling back to a backup copy. .DESCRIPTION Uses Repair-VHD if possible. If that fails, mounts the VHDX read-only, runs chkdsk, and then replaces with a backup if corruption persists. #> param( [Parameter(Mandatory=$true)] [string]$VhdPath,

Write-Warning "Automatic repair incomplete. Manual inspection required." | Error | Cause | PowerShell Fix | |-------|-------|----------------| | The VHDX is corrupt | Header or metadata damage | Use Repair-VHD with healthy copy | | The system cannot find the file specified | Path issue or missing parent (differencing) | Provide full absolute path | | Access denied | Permission or locked file | Run as Administrator; ensure no VM attached | | The parameter is incorrect | Fixed-size VHDX passed to Repair-VHD | Convert to dynamic first: Convert-VHD -Path file.vhdx -Destination dynamic.vhdx -VHDType Dynamic | | The VHDX chain is broken | Missing parent in differencing chain | Use Get-VHD -Path child.vhdx -ParentPath to locate parent; restore parent | Checking VHDX Health Without Repair # Health check function function Test-VHDXHealth param([string]$Path) try $vhd = Get-VHD -Path $Path -ErrorAction Stop switch ($vhd.State) "OK" Write-Host "Healthy" -ForegroundColor Green "Corrupted" Write-Host "Corrupt - Needs repair" -ForegroundColor Red "Mounted" Write-Host "Mounted & OK" -ForegroundColor Cyan default Write-Host "Unknown: $($vhd.State)" -ForegroundColor Yellow $vhd catch Write-Error "Cannot read VHDX: $_"

catch Write-Warning "Repair-VHD failed: $($_.Exception.Message)" Write-Host "Attempting mount + chkdsk recovery..." $mountResult = Mount-VHD -Path $VhdPath -ReadOnly -PassThru -ErrorAction SilentlyContinue if ($mountResult) $disk = Get-Disk -Number $mountResult.Number -ErrorAction SilentlyContinue if ($disk) Where-Object $_.DriveLetter if ($partition) $driveLetter = "$($partition.DriveLetter):" Write-Host "Running chkdsk on $driveLetter..." & chkdsk $driveLetter /f /r /x Dismount-VHD -Path $VhdPath Write-Host "Chkdsk completed. Attempt to remount VHDX manually to verify." repair vhdx powershell

Repair-VHD -Path "C:\CorruptedVMs\server01.vhdx" -Path "D:\Backups\healthy_server01.vhdx" -Passthru

[Parameter(Mandatory=$false)] [string]$BackupPath = "$env:TEMP\vhdx_backup_$(Get-Date -Format 'yyyyMMdd_HHmmss').vhdx" ) if (-not (Get-Module -ListAvailable -Name Hyper-V)) Write-Error "Hyper-V PowerShell module is required." exit 1 # Recreate the differencing disk from healthy parent

# Get the volume letter (e.g., F:) chkdsk F: /f /r /x For non-structural corruption (e.g., block allocation issues):

[Parameter(Mandatory=$true)] [string]$HealthyCopyPath, param( [Parameter(Mandatory=$true)] [string]$VhdPath

$fixedVHD = Repair-VHD -Path "E:\Corrupt\data.vhdx" -Path "F:\Backups\data_clean.vhdx" -Passthru $fixedVHD | Format-List *