Jase McCarty, VMware Certified Professional (VCP), published on his blog a notable trick to achieve on-the-fly modification of Microsoft Windows virtual machines templates in a VMware ESX Server with VirtualCenter infrastructure at deployment time:
What is my objective:
To be able to take a standard Clone, or Template, and deploy it with a root partition size greater than the original Clone, or Template, without using any third party tools.
Why is this useful:
By giving the ability to deploy Windows VM?s with variable sizes, less templates will be necessary, while being more flexible with regards to virtual disk space…
Read the whole paper at source.