Snapshot Management with PowerCli

I’ve been doing some lab work recently, testing out some new automation for deploying Dell EMC Enterprise Hybrid Cloud (EHC) and as part of the testing we needed to be able to quickly and easily create on the fly rollback points at incremental steps in the build to assist with troubleshooting (outside of the standard rollback points created by the EHC Automated Install Tool (AIT) ).

Note: AIT is currently an internal Dell EMC tool used by our professional services organisation to deploy and configure EHC on a customer site.

Disclaimer: As with all scripts and code that you find on the web you should thoroughly test this in a lab environment before considering to use it in production. This script comes with zero warranty as it was something that was created quickly for lab use only!

Snapshots were enough to give us a rollback point, so to achieve this I put together a menu based PowerCli script that will take snapshots of a defined list of VMs with a defined snapshot name, rollback to the last snap taken, or rollback to a defined snapshot.

For more information on how to add a menu to a PowerShell script go here, and for how to add a “Press any key to continue..” to a script go here.

Here is the script for snapshot management. It is broken up into the following PowerShell Functions:

• CreateVMSnapshot
• RevertLastVMSnapshot
• RevertSpecificVMSnapshot
• anyKey
• Menu

Before running the script you need to edit the user variables for your environment. The $VMList variable is a comma separated list of VM names as they appear in vCenter. In my example these are the components of a distributed vRA deployment. The $SnapshotName vaiable will be used when creating snapshots or when executing the Revert To Specific Snapshot option

# User Variables
$vCenterFQDN = "vcs01.domain.local"
$vCenterUser = "administrator@vsphere.local"
$vCenterPassword = "Password123!"
$VMList = @("vra01", "vra02", "web01", "web02", "mgr01", "mgr02", "dem01", "dem02", "agt01", "agt02")
$SnapshotName = "Snap01"

To execute the script just browse to the directory you saved the script in a PowerShell or PowerCli console, run ./SnapshotManagement.ps1 and you will be presented with a menu

Select the desired option from the menu. The operations are running Async so are quite quick to complete.

The raw code is below. I’ve also posted the script to GitHub here

# User Variables
$vCenterFQDN = "vcs01.domain.local"
$vCenterUser = "administrator@vsphere.local"
$vCenterPassword = "Password123!"
$VMList = @("vra01", "vra02", "web01", "web02", "mgr01", "mgr02", "dem01", "dem02", "agt01", "agt02")
$SnapshotName = "Snap01"
###############################
# DO NOT EDIT BELOW THIS LINE #
###############################
# Add Required Snappins
Get-Module -ListAvailable VM* | Import-Module

Function CreateVMSnapshot {
# Connect to vCenter
Connect-VIServer $vCenterFQDN -username $vCenterUser -password $vCenterPassword
	Foreach ($VM in $VMList) {
	Write-Host "Creating Snapshot for $VM"
	New-Snapshot -VM $VM -Memory -quiesce -Name $SnapshotName -RunAsync
							 }							 
									}
									
Function RevertLastVMSnapshot {
# Connect to vCenter
Connect-VIServer $vCenterFQDN -username $vCenterUser -password $vCenterPassword
	Foreach ($VM in $VMList) {
	Write-Host "Reverting Snapshot for $VM"
	$snap = Get-Snapshot -VM $VM | Sort-Object -Property Created -Descending | Select -First 1
    Set-VM -VM $vm -SnapShot $snap -Confirm:$false  -RunAsync | Out-Null
							 }							 
									}

Function RevertSpecificVMSnapshot {
# Connect to vCenter
Connect-VIServer $vCenterFQDN -username $vCenterUser -password $vCenterPassword
	Foreach ($VM in $VMList) {
	Write-Host "Reverting Snapshot for $VM"
	#$snap = Get-Snapshot -VM $VM | Sort-Object -Property Created -Descending | Select -First 1
    Set-VM -VM $vm -SnapShot $SnapshotName -Confirm:$false  -RunAsync | Out-Null
							 }							 
									}									

Function anyKey 
{
    Write-Host -NoNewline -Object 'Press any key to return to the main menu...' -ForegroundColor Yellow
    $null = $Host.UI.RawUI.ReadKey('NoEcho,IncludeKeyDown')
    Menu
}
									
Function Menu 
{
    Clear-Host         
    Do
    {
        Clear-Host                                                                        
        Write-Host -Object 'Please choose an option'
        Write-Host     -Object '**********************'	
        Write-Host -Object 'Snapshot VM Options' -ForegroundColor Yellow
        Write-Host     -Object '**********************'
        Write-Host -Object '1.  Snapshot VMs '
		Write-Host -Object ''
        Write-Host -Object '2.  Revert to Last Snapshot '
		Write-Host -Object ''
		Write-Host -Object '3.  Revert To Specific Snapshot '
		Write-Host -Object ''
        Write-Host -Object '4.  Exit'
        Write-Host -Object $errout
        $Menu = Read-Host -Prompt '(0-3)'

        switch ($Menu) 
        {
           1 
            {
                CreateVMSnapshot 			
                anyKey
            }
            2 
            {
                RevertLastVMSnapshot
                anyKey
            }
			3 
            {
                RevertSpecificVMSnapshot
                anyKey
            }
            4 
            {
                Exit
			}	
            default 
            {
                $errout = 'Invalid option please try again........Try 0-4 only'
            }

        }
    }
    until ($Menu -ne '')
}   

# Launch The Menu
Menu