Detach and Remove Disk from VM

Simple, annoying task

Those kind I love. Why? Cause I can automate them

Here’s the story - a VM on a Hyper-V host with a bunch of disks, that are no longer needed. Task:

• disable (set to offline)
• remove from VM configuration
• remove from disk

The hardest part was to map disk number from within OS to disk attached in VM configuration. It seems that Location from VM configuration maps to LUN number in Location within the Windows OS. That’s great!

Disclaimer

THIS IS A SCRIPT, NOT A FUNCTION

Bear in mind this is an interactive script that is supposed to be run with caution! Re-check your variables before removing. This is a dirty soltuion to get the task done!

Consider yourself warned!

Let’s get to work

• initialize variables

$Credential = Get-Credential

$VMConnectionProps = @{
    ComputerName = 'TestVM' #VMName
}
$HostConnectionProps =@{
    ComputerName = 'HyperVHost1' #HyperV Host Name
}

if ($Credential) {
    $VMConnectionProps.Credential = $Credential
    $HostConnectionProps.Credential = $Credential
}

• using Out-GridView select which disks to process

$disksToDisable =  Invoke-Command @VMConnectionProps -ScriptBlock {
    Get-Disk | where-object {$null -ne $PSItem.Number } 
} | Out-GridView -PassThru

• set disks to offline

if ($disksToDisable) {
    Invoke-Command @VMConnectionProps -ScriptBlock {
        foreach ($disk in $USING:disksToDisable) {
            Write-Host "Processing with disk - [$($disk.FriendlyName)] to disable."
            Set-Disk -InputObject $disk -IsOffline $true
        }
    }
}

• get vhdx files attached to VM (from VM configuration)

$VMDisks = Invoke-Command @HostConnectionProps -ScriptBlock {
    Get-VM -Name $USING:VMConnectionProps.ComputerName | Select-Object -ExpandProperty HardDrives
}

• compare and get final list of disks

$ToDelete= foreach ($diskToDisable in $disksToDisable) {
    $VMDisks | Where-Object {$PSItem.ControllerLocation -eq $diskToDisable.Number}
}

• detach disks from VM

foreach ($disk in $ToDelete) {
    Write-Host "Processing VM [$($VMConnectionProp.ComputerName)] on Host [$($HostConnectionProps.ComputerName)] - Removing disk [$($disk.ControllerLocation)] with Path [$($disk.Path)]"
    Invoke-Command @HostConnectionProps -ScriptBlock {
        $removeVMHardDiskDriveSplat = @{
            ControllerType     = $USING:disk.ControllerType
            ControllerNumber   = $USING:disk.ControllerNumber
            VMName             = $USING:VMConnectionProps.ComputerName
            ControllerLocation = $USING:disk.controllerLocation
        }
        Remove-VMHardDiskDrive @removeVMHardDiskDriveSplat
    }
}

• remove vhdx from Hyper-V

Invoke-Command @HostConnectionProps -ScriptBlock {
    foreach ($disk in $USING:ToDelete) {
        Remove-Item -Path $disk.Path 
    }
}

Full script

Here’s the full script

$Credential = Get-Credential

$VMConnectionProps = @{
    ComputerName = 'TestVM' #VMName
}
$HostConnectionProps =@{
    ComputerName = 'HyperVHost1' #HyperV Host Name
}

if ($Credential) {
    $VMConnectionProps.Credential = $Credential
    $HostConnectionProps.Credential = $Credential
}

#Get specifc disks from VM
$disksToDisable =  Invoke-Command @VMConnectionProps -ScriptBlock {
    Get-Disk | where-object {$null -ne $PSItem.Number } 
} | Out-GridView -PassThru

#Set disk to offline
if ($disksToDisable) {
    Invoke-Command @VMConnectionProps -ScriptBlock {
        foreach ($disk in $USING:disksToDisable) {
            Write-Host "Processing with disk - [$($disk.FriendlyName)] to disable."
            Set-Disk -InputObject $disk -IsOffline $true
        }
    }
}

#Get disks attached to VM
$VMDisks = Invoke-Command @HostConnectionProps -ScriptBlock {
    Get-VM -Name $USING:VMConnectionProps.ComputerName | Select-Object -ExpandProperty HardDrives
}

#get vhdx to disable and delete
$ToDelete= foreach ($diskToDisable in $disksToDisable) {
    $VMDisks | Where-Object {$PSItem.ControllerLocation -eq $diskToDisable.Number}
}

#detach disk from VM
foreach ($disk in $ToDelete) {
    Write-Host "Processing VM [$($VMConnectionProp.ComputerName)] on Host [$($HostConnectionProps.ComputerName)] - Removing disk [$($disk.ControllerLocation)] with Path [$($disk.Path)]"
    Invoke-Command @HostConnectionProps -ScriptBlock {
        $removeVMHardDiskDriveSplat = @{
            ControllerType     = $USING:disk.ControllerType
            ControllerNumber   = $USING:disk.ControllerNumber
            VMName             = $USING:VMConnectionProps.ComputerName
            ControllerLocation = $USING:disk.controllerLocation
        }
        Remove-VMHardDiskDrive @removeVMHardDiskDriveSplat
    }
}
#remove vhdx from Hyper-V
Invoke-Command @HostConnectionProps -ScriptBlock {
    foreach ($disk in $USING:ToDelete) {
        Remove-Item -Path $disk.Path 
    }
}