Golden Image and Cloning
Introduction
Virtual environments have revolutionized modern IT infrastructure by providing scalability, flexibility, and cost-efficiency. Among the many techniques used to manage virtual machines (VMs), golden images and cloning are two of the most powerful strategies for ensuring consistency, rapid deployment, and ease of management.
What is a Golden Image?
A golden image, also known as a master image or template, is a pre-configured, baseline image of a system. It typically includes:
- A base operating system
- Required software packages
- System configurations and policies
- Security patches and updates
Once created, this image serves as a standardized template for spinning up new virtual machines quickly and uniformly.
Benefits of Using Golden Images:
- Consistency: All deployed VMs start from the same clean state.
- Speed: Rapid provisioning of new machines.
- Security: Ensures machines are patched and hardened before deployment.
- Efficiency: Reduces time spent on manual configuration.
Cloning
Cloning refers to the process of creating an exact copy of an existing virtual machine.
Cloning is widely used for:
- Testing and development environments
- Load-balanced deployments
- Temporary environments
Golden images and cloning simplify VM deployment and ensure environment consistency. Whether you're managing a small development lab or a large-scale enterprise cloud infrastructure, mastering these techniques is key to operational efficiency and reliability.
Citrix VDI Environments
In Citrix Virtual Desktop Infrastructure (VDI), efficient and scalable desktop deployment is critical. Two foundational strategies to streamline this process are the use of golden images and cloning. These techniques ensure fast, consistent, and secure delivery of virtual desktops across an enterprise.
What is a Golden Image in Citrix?
In Citrix environments, a golden image—also referred to as a Master Image—is a single, standardized virtual machine (VM) that contains:
- A base Windows OS (e.g., Windows 10/11)
- Required business applications
- Citrix Virtual Delivery Agent (VDA)
- Configuration settings and GPOs
- Security patches and updates
Once finalized, this golden image becomes the single source of truth for deploying virtual desktops across multiple users or departments.
Key Role in Citrix:
- Used by Machine Creation Services (MCS) or Provisioning Services (PVS) to create non-persistent desktops.
- Supports centralized updates—just update the master image, and recompose the desktops.
Cloning in Citrix VDI
While traditional cloning (full or linked) is used in some environments, Citrix uses MCS and PVS to “clone” desktops efficiently.
Machine Creation Services (MCS)
MCS is a Citrix tool that clones VMs from the master image by creating:
- A base disk (copy of the golden image)
- A delta disk (writes per user session)
- Optional identity disk (stores machine identity info)
Advantages:
- Simple to set up and maintain
- Integrates with hypervisors (e.g., VMware, Hyper-V, Citrix Hypervisor)
Provisioning Services (PVS)
PVS streams the OS over the network from a virtual disk (vDisk) to target machines.
Advantages:
- Extremely fast boot times
- Minimal storage footprint
- Ideal for large environments with shared hardware
Workflow: Creating a Golden Image in Citrix VDI
- Set up a clean VM with your base OS and updates.
- Install required apps and Citrix VDA.
- Perform system optimization (disable unnecessary services, apply Citrix-recommended tweaks).
- Run sealing tools (e.g., Sysprep if using MCS).
- Snapshot the VM and use it as your golden image.
- Publish using MCS or PVS.
Benefits of Golden Image Strategy in Citrix
- Rapid Deployment: Instantly provision desktops to users.
- Consistency: Uniform desktop experience across the organization.
- Simplified Maintenance: Update the golden image and redeploy.
- Security: Fewer entry points due to standardized configurations.
Summary
In Citrix VDI environments, the combination of golden images and image-based provisioning via MCS or PVS is essential for delivering fast, reliable, and secure virtual desktops. By leveraging a well-maintained master image, organizations can significantly reduce overhead and enhance the user experience.
Xshield Agent
The Xshield agent supports being installed as part of a golden image in a virtual environment and can be cloned as part of the cloning function of the environment.
There are two models of operation:
- Standalone Golden Image
- All images are Golden image candidates
Standalone Golden Image
This is usually the default model of operation in most enterprise, where they dedicate a single machine or VM as the golden image VM.
The Xshield agent must be installed this machine and registered by using an extra command line argument to indicate that it is part of a golden image (--golden-image=true). This flag ensures that the Xshield agent software is installed but the service is not brought up and hence will never connect with the Xshield security platform.
Now a clone operation of this golden image will ensure the duplication of the Xshield agent and its configuration files on the cloned VM. However, the Xshield agent on the cloned VMs will actually register with the Xshield security platform.
In this model, all software updates (including the Xshield agent) will happen only on the golden image VM or Machine. Once the patching updates are complete, then the cloning operation will be performed again. Since the Xshield agent uses the underlying VM's property to build its unique Asset Identifier (which is used by the Xshield security platform to uniquely identify the asset), the new cloned image when applied to the same VM will result in the Xshield agent having the same Asset Identifier and hence will show up as the same asset on the platform post the cloning.
Equivalent Golden Images (Omni clones)
In this situation, the administrator doesn't want to have a dedicated machine as the one having the golden image (and non-operational). Instead, the user prefers to make the golden image once and then clone it to multiple VMs. All VMs including the one hosting the golden image are operational and hence the Xshield agents running on those VMs will register with the Xshield security platform including the one on the VM hosting the first golden image.
Post this point, the operator can treat any of these operational VM as the golden image candidate for future upgrades and patches. Once they are applied on that machine, then new clones will be created and applied to the existing VMs.
In this model, a separate script (downloaded separately) must be executed ONCE the first golden image is created with the Xshield agent. This script ensures that this machine can be cloned and at the same time the Xshield agent on this machine can register with the Xshield security platform (along with the cloned agents). The command to execute is
- .\golden-image-deterministic-id.ps1 -CT_DEPLOYMENT_KEY "PLACE_HOLDER" -CT_DOMAIN "PLACE_HOLDER" -CT_AGENT_VERSION "PLACE_HOLDER" -CT_AGENT_TYPE "PLACE_HOLDER" -CT_AUTO_UPGRADE "PLACE_HOLDER"
Summary
The Xshield agent has the necessary support to be part of a golden image and the properties of being cloned. For more information, please contact the ColorTokens Support or Sales team.