The question of “whether we should do “thick” or “thin” images” comes up a lot and so in this I’m going to go through my thought process when answering this question and hopefully, help you in making the right choice for your environment.
First, lets define the different image types and show the processes for each.
Thick Images
Thick images are an image which is created by an admin containing the Windows installation, Windows updates, applications, application updates and customisations such as - registry changes, Start menu layout and application configurations. Files and configuration changes that are “baked in” to your Windows installation.
The image creation process looks something like this:
- Windows installed on VM.
- Check for Windows updates and install.
- Applications installed.
- Applications updated.
- Check for Windows updates and install.
- Customise Windows and applications.
- Capture image.
The image is then deployed to devices. That process is as follows:
- Deploy image to device(s).
- Drivers installed.
- Join domain.
- Check for Windows updates, yet again, just in case.
- Install applications that need to be installed on final deployment or are subject to frequent updating - anti virus or remote management clients for example.
- Any final tweaks that are subject to frequent updates.
Thin Images
Thin images are more of a process in which the Windows image provided from Microsoft is deployed and then updates, applications and any customisations are made as part of a task sequence, group policy or other management system.
The deployment process looks something like this:
- Windows image deployed to device(s).
- Drivers installed.
- Join domain.
- Check for Windows updates and install.
- Applications installed.
- Applications updated.
- Check for Windows updates and install.
- Customise Windows and applications.
Image Times For Thick/Thin
These times are taken from my image creation and deployment process in my lab. I’m using Hyper-V VMs for the server and client devices. These times are only intended as demonstration purposes.
OS: Windows 10 22H2
Customisations: Remove specific MS Store Apps, script to configure various Windows settings for all users.
Apps: Visual C++ 2017 Redist, .NET 3.1 Desktop Runtime, .NET 5 Desktop Runtime, .NET 6 Desktop Runtime, .NET Framework 3.5, .NET Framework 4.8, 7-zip, Firefox, Google Chrome, Notepad++, OBS Studio, Epic Games Launcher, Ubisoft Connect, Steam Client, Origin, VLC, Adobe Reader, Office 365 Business
Thick Image
- Build - Apps, Windows updates from internet, Customisations: 56m 00s
- Deploy - Windows updates from internet, Customisations - 9m 55s
Thin Image
- Deploy - Apps, Windows updates from internet, Customisations - 1h 00m 17s
You can see for yourself from the times above, thick images put a lot of time into creating the image and deployment is fast, where as the thin image is a longer process to deploy but there is no creation phase making thin images more agile. But this isn’t so say that you can’t combine both methods.
When To Use Thick/Thin
Each of the image types is suited to different situations. For example, if you are deploying a large batch of computers all at once for a classroom, then it would be best to build a thick image on a virtual machine with everything installed and configured as needed and then deploy to the devices.
However, if you are deploying devices in smaller batches over a longer period of time, then the thin image makes more sense because the thick image will be out-of-date and the time needed to install Windows updates and application updates will make the process longer and any time savings that you made from creating a thick image in the first place will be negligible.
Why Not Both?
You can use a combination of both methods if needed. For example if you are using a older version of Adobe’s Creative Suite - a large install that doesn’t get updates these days, then rather than deploy a thin image and install this for each device you could create a Windows images with this and any other large applications that don’t get updates or the updates are quick to install further downstream.
Another way to use both is to have a thick image for large deployments and then a thin image for the devices that trickle in. The downside of this is that you have more to maintain, potentially a “Build” task sequence, “Deploy” task sequence and a “Deploy-Thin” task sequence and everything that comes with it.
Ultimately the choice is yours - you make the best decision you can for your environment, workflow and team. But at least you have choice.
If you have any questions or comments, please leave them below.
-Mike