Locate Azure VMs that aren't being backed up

Azure-Find-VMs-Not-Backed-Up.ps1

# Find VMs which aren't backed up by Azure
#
# Sam Crossman (https://github.com/sam-cross)

# You'll need the Az PowerShell module for this :)
# Set subscription via Set-AzContext before running this script

$SubscriptionName = (Get-AzContext).Subscription.Name

# Enumerate all VMs in all backup vaults within the subscription
$VMIDs_AllVaults = @()
foreach ($VaultResource in (Get-AzResource -ResourceType "Microsoft.RecoveryServices/vaults")) {
    Write-Output "Searching Vault $($VaultResource.Name)..."

    Get-AzRecoveryServicesVault -Name $VaultResource.Name -ResourceGroupName $VaultResource.ResourceGroupName | Set-AzRecoveryServicesVaultContext

    $VaultContainers = Get-AzRecoveryServicesBackupContainer -ContainerType "AzureVM" -Status "Registered"

    Foreach ($VaultContainer in $VaultContainers) {
        $VMIDs_AllVaults += Get-AzRecoveryServicesBackupItem -Container $VaultContainer -WorkloadType "AzureVM" | Select-Object VirtualMachineId
    }
}

# Get all VMs in subscription - don't filter by RSG
$VMs = Get-AzVM

# Log every VM which is not found in All Vaults
Foreach ($VMResource in $VMs) {
    $j = 0;
    For ($i=0; $i -lt $VMIDs_AllVaults.Count; $i++) {
        If ($VMResource.Id -eq $VMIDs_AllVaults[$i].VirtualMachineId) { $j++ }
    }

    If ($j -eq 0) {
        Write-Host "Virtual Machine $($VMResource.Name) is NOT currently in a backup vault"
        Write-Output "$($VMResource.Name)" >> "C:\Temp\AzureVMsNotBackedUp-$($SubscriptionName).txt"
    }
}