Public/New-AzVmSnapshot.ps1

function New-AzVmSnapshot {
    [CmdletBinding(SupportsShouldProcess, ConfirmImpact = 'High')]
    param
    (
        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string[]]$VmName,
 
        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string]$ResourceGroupName
    )
    
    $jobs = @()
    foreach ($name in $VMName) {
        $scriptBlock = {
            param($ResourceGroupName, $VmName)

            $ErrorActionPreference = 'Stop'

            $snapshotName = "AzVmSnapshot-$VMName-$(Get-Date -UFormat '%Y%m%d%H%M%S')"

            $vm = Get-AzVm -ResourceGroup $ResourceGroupName -Name $VmName
            $stopParams = @{
                ResourceGroupName = $ResourceGroupName
                Force             = $true
            }
            try {
                Write-Verbose -Message "Stopping Azure VM [$($VmName)]..."
                $null = $vm | Stop-AzVm -ResourceGroupName $ResourceGroupName -Force

                $diskName = $vm.StorageProfile.OSDisk.Name
                $osDisk = Get-AzDisk -ResourceGroupName $ResourceGroupName -DiskName $diskname
                $snapConfig = New-AzSnapshotConfig -SourceUri $osDisk.Id -CreateOption Copy -Location $vm.Location 
                Write-Verbose -Message "Creating snapshot..."
                $null = New-AzSnapshot -Snapshot $snapConfig -SnapshotName $snapshotName -ResourceGroupName $ResourceGroupName
            } catch {
                throw $_.Exception.Message
            } finally {
                Write-Verbose -Message "Starting Azure VM back up..."
                $null = $vm | Start-AzVm
                [pscustomobject]@{
                    'VMName'       = $VmName
                    'SnapshotName' = $snapshotName
                }
            }
        }
        $jobs += Start-Job -ScriptBlock $scriptBlock -ArgumentList @($ResourceGroupName, $name)
    }
    Write-Verbose -Message 'Executed all snapshot operations. Waiting on jobs to finish...'
    $jobs | Wait-Job | Receive-Job
}