Instant clones are a different feature from what is called "Linked Clones" in any Hypervisor (VirtualBox, VMware Workstation, and also ESXi).
It looks like a funky feature, but does not help in my (and likely the original asker's) use case.
Here is the overview simplified ...
1. power off source VM
2. create new snapshot
3. create new dir
4. copy vmx and new snapshot to the new dir
5. modify identity of the copied vmx-file
6. edit path to parentfile in the new snapshot descriptor vmdk
7. register new vmx-file
Thats the quick and easy variant.
All you need is putty or winscp
This is really a hacky way of doing it.
And I can tell from experience that this is going to get you into trouble, e.g. once you have to move the VMs to a different server.
Or if you delete a base VM snapshot by mistake, you break all of your linked clones.
It can get nightmarish...
The original feature was part of Horizon/VDI i think. Ulli describes how to do it manually.
Scott is right about the Instant Clone feature which can do the same and much,much more. But OP says he have ESXi 6.5 and the blog articles says 6.7 and up. Also no "easy" GUI.
Thank you for your thoughts and ideas.
I had a look now at the instant clone post (Instant Clone in vSphere 6.7 rocks! | Yellow Bricks ), and it really does look very efficient.
Also the idea of a "parentless" clone.
But to the non-expert user of vSphere, this looks more like an experimental feature - even though I did manage to find out how to use a "Managed Object Browser" after some googling.
But let me explain the use case here: Dynamic malware analysis on Windows machines, where you need to run a lot of machines in parallel.
The examples I saw for instant cloning always clone some Linux machines, where you don't have issues with license activation for a start. If I instantly clone Windows machines, the machines (and other software like MS Office on the machines) will go into unlicensed state after a short time, and stop working.
In any case, I am happy to look more deeply into instant cloning, but I do miss a simply UI option to create "thin" clones.
The way I understood it is that Instant Clones are basically throwaway machines - you clone them, use them for a short time, and when you shut them down, they are gone.
This can indeed pose problems regarding Windows and Office activations.
Can somebody point me to the right documentation regarding this?
Also Instant Clones are only a feature included in VMware Horizon which is much more expensive than vSphere.
Without Horizon, you have to script the automation yourself, correct?