Deploying and Cloning VMs with PowerCLI: Templates, Customization, and Automation at Scale

Introduction

Manual VM deployment can become a bottleneck as environments scale. PowerCLI simplifies this by automating provisioning tasks with reusable templates, guest OS customization, and consistent configuration logic. This article focuses on deploying and cloning VMs programmatically to reduce time, human error, and configuration drift.

My Personal Repository on GitHub

VMware Repository on GitHub

VM Deployment Approaches with PowerCLI

PowerCLI supports three main automation methods:

• Deploying VMs from a vSphere template
• Cloning existing VMs with customizations
• Creating new VMs from scratch using configurations

This article will focus on template-based deployment and cloning. These methods allow for consistent guest OS, hardware, network, and storage settings.

Prerequisites

Before deploying VMs, ensure:

• You are connected to vCenter using Connect-VIServer
• A VM template exists in a content library or folder
• A customization spec is created in vCenter
• You have rights to create VMs in the target cluster, folder, and datastore

Method 1: Deploy VM from Template

Step 1: List Available Templates

Get-Template

Step 2: List Customization Specs

Get-OSCustomizationSpec

Step 3: Deploy VM with Specified Configuration

New-VM -Name "WebApp01" `
       -Template "Win2019-Base" `
       -VMHost "esxi01.lab.local" `
       -Datastore "DS1" `
       -OSCustomizationSpec "Win2019-Secure" `
       -ResourcePool "Production" `
       -Location "Production VMs"

This command deploys a Windows Server 2019 VM with a predefined customization spec, including hostname, IP address, and domain join.

Method 2: Clone Existing VM

This is useful when the VM is not a template but is a good base image.

Get-VM -Name "WebApp-Golden" | New-VM -Name "WebApp-Clone01" -VMHost "esxi02.lab.local" -Datastore "DS2"

Use this only if the source VM is powered off. Alternatively, use linked clones for lab or training environments.

Method 3: Bulk Deployment Using CSV Input

You can deploy multiple VMs from a CSV input file. Example CSV:

Name,Template,Datastore,VMHost,CustomizationSpec
SQL01,Win2019-Base,DS1,esxi01.lab.local,SQL-Spec
SQL02,Win2019-Base,DS2,esxi02.lab.local,SQL-Spec

PowerCLI Script

$vmList = Import-Csv -Path "C:\VM_Deployments.csv"

foreach ($vm in $vmList) {
    New-VM -Name $vm.Name `
           -Template $vm.Template `
           -Datastore $vm.Datastore `
           -VMHost $vm.VMHost `
           -OSCustomizationSpec $vm.CustomizationSpec `
           -ResourcePool "Production"
}

Customizing Guest OS Configurations

If your environment uses static IPs or needs custom post-deployment tasks, use New-OSCustomizationSpec or Set-OSCustomizationNicMapping.

# Update NIC mapping with a static IP
$spec = Get-OSCustomizationSpec -Name "SQL-Spec"
Set-OSCustomizationNicMapping -OSCustomizationSpec $spec `
    -Position 1 -IpMode UseStaticIP `
    -IpAddress "192.168.10.101" -SubnetMask "255.255.255.0" `
    -DefaultGateway "192.168.10.1"

Diagram: Deployment Flow

Real-World Use Case: Weekly Lab Refresh

Some environments require full refresh of dev or QA environments from a golden image. Use PowerCLI to:

• Delete old lab VMs
• Deploy fresh ones from template
• Apply NIC and name customization

$labVMs = "Lab01", "Lab02", "Lab03"
foreach ($vm in $labVMs) {
    Remove-VM -VM $vm -DeletePermanently -Confirm:$false
    New-VM -Name $vm -Template "Lab-Template" -VMHost "esxi01" -Datastore "Lab-DS"
}

Troubleshooting Tips

What’s Next

The next article will focus on Host Configuration and Compliance, including:

• Configuring networking with PowerCLI
• Applying host profiles and patches
• Validating settings across the cluster