Difference between VM Template and VM Cloning

[iamtez]

I would like to understand the difference between using a VM Template vs cloning a VM. I could not find any information on best practices for using a VM template. Here is what I want to achieve and I am trying to pick the best possible way to do this.

I want to have some base VMs (these will be either templates or actual VMs from which clone can be created later) created and stored in a shared storage. Then I want users to be able to pick any VM, create a clone out of it or make a VM from the template and use it. I know this might suggest that cloning might be the way to go but I want to make sure using templates would not be useful and quicker.

I would really appreciate any help on this.

[SuryaVMware]

Template is a gold image of a specific OS with all the packages/Application, Software settings and policies that suites your organization.

You might have to do additional customization like adding few more software or defining the Role of the OS running inside the VM. but you dont have to build everyt thing from scratch.

A clone is a exact copy of the VM at the given point when you are taking a clone. If you have 2 different groups using a particular VM and that they dont want to do that any more, because they needs are not the same any more. You can clone the VM and give each team a VM of their own so that the further cutomization suiting their needs can be done with out any dependancy.

Hope this helps. Let me know if you need more information.

-Surya

[iamtez]

Thanks a lot for that information.

From your reply though, I still do not see any significant difference in using one vs the other. For instance, I would like to create a VM with the OS and some software installed which will act something like an image. Then users will create VMs out of this image and do whatever they want with their own copy. For this purpose, I believe I can use a template or an actual VM as the image, is that correct?

If yes, then is there a time penalty is terms of using one over the other?

-Tejas

[SuryaVMware]

Let me give you a better example. You need to setup some 100 VMs with a basic set of software including OS. Template is the solution and template is originally a VM which underwent through the process of installaion of OS and all other software that you want. So when ever any one in the organization request of that particular OS you have the same set of software ready available for them. Like a basic desktop is a good exaple here. every one gets a desktop/laptop with the same software as a organization policy.

Where a Cloning let's assume there is work in progress and then you have 2 paths to take from here. Like you need to upgrade to beta and more stable build. you can clone your VM, which meets all the prerequesits of the application that you are planning to test and then you can use a VM each for beta and stable testing.

The conclusion is a Clone can be an exact copy of a running VM at the time of cloning process where as a template is the baseline image with the predefined organization standards

Hope I am more clear this time.

-Surya

[iamtez]

Great. Thanks a lot to both Surya and Bill. I think I know what to use for my current needs. I really appreciate your help.

[billhill]

A Template is really just a Virtual Machine that you cannot run.

You build the template as a Virtual Machine. Once you have the Virtual Machine configured to exactly how you want it, you shut it down and, via Virtual Center or the VI Client, right click on the VM and select Convert to Template.

This template can be used to deploy other Virtual Machines that you would like to have the same characteristics as the template (perhaps a workstation image for VDI or if your company has a standard Linux Web Server build). After a machine is deployed from a template, the machine is completely independant from the template.

Additionally, you can convert the template back to a virtual machine to update it (run Windows update, for example) so that any future deployments are updated as well.

A template only consumes disk space seeing as it cannot be run.

Cloning is actually just creating an exact copy of the Virtual Machine. However, the clone source (the original machine) can be restarted.

In your situation, I would suggest creating a template. A clone would require the source VM be shut down in order to copy it. The template could be deployed at any time without interrupting any other machines.

I hope that helps!

~Bill