Automate Hyper-V checkpoints with PowerShell and Task Scheduler

2023-04-04

This script will keep n many checkpoints (or snapshots) of a Hyper-V virtual machines for a given VM’s name.

Usage:

powershell.exe scriptname.ps1 7 RedHatDockerHost

Where you want to keep 7 checkpoints for a VM named RedHatDockerHost

The script

Note: the term ‘days’ is used in the script, assuming that this script is run daily, however ‘runs’ would have been more accurate

# Keep X days of Hyper-V checkpoints for VM Y
param(
    [Parameter(Mandatory=$True, Position=0, ValueFromPipeline=$false)]
    [int]
    $days,

    [Parameter(Mandatory=$True, Position=1, ValueFromPipeline=$false)]
    [System.String]
    $name
)


# Check VM exists

$vmExists = get-vm "$($name)"

if ($vmExists.ExitCode -eq "False") {
	"VM $name does not exist! Exiting."
	exit
}

# Rename any existing checkpoints

for ($dayCount = $days ; $dayCount -gt 0 ; $dayCount--) {
	$toDay = $dayCount + 1

	try {
		# Check a checkpoint for this day exists
		get-vmcheckpoint -vmname $name -name "$($name)_$($dayCount)_auto"

		# Rename
		rename-vmcheckpoint -name "$($name)_$($dayCount)_auto" -vmname $name -newname "$($name)_$($toDay)_auto"
	} catch [ObjectNotFound,Microsoft.HyperV.PowerShell.Commands.GetVMSnapshot] {
		# Do nothing
	}
}

# Create new checkpoint

$checkpointingSuccess = checkpoint-vm -name $name -snapshotname "$($name)_1_auto"

if ($checkpointingSuccess.ExitCode -eq "False") {
	"Failed to create new checkpoint. Exiting."
	exit
}

# Delete old checkpoint

$delDay = $days + 1;
#"Deleting $delDay"
Remove-vmcheckpoint -vmname $name -name "$($name)_$($delDay)_auto"

Set it up

• Create the script
  • Copy and paste the above script into notepad and save as createcheckpoint.ps1

• Create the task
  • Open Task Scheduler
  • On the left-hand side, right-click Task Scheduler Library and click Create Basic Task
  • Enter a Name e.g., Checkpoint RedHatDockerHost
  • Choose a schedule e.g., Daily
  • For Action choose Start a program
    • For Program/script enter powershell.exe
    • In Add arguments, enter the full path to the script created in the first step, the number of checkpoints to keep, and the name of the VM to checkpoint e.g., “C:\FILES\createcheckpoint.ps1” 7 “RedHatDockerHost”
  • Click Finish
• Modify the task
  • Open the task you just created
  • Choose Run whether user is logged on or not
  • (If not on a domain joined PC) tick Do not store password
  • Tick Run with highest privileges
  • Tick Hidden
  • Click OK
• Follow up!
  • Set a reminder to check for the next few days/occurances that your task is working! Backups (this isn’t a proper backup but it provides more safety than not having it) are only useful if they are tested to work.