IBM provides an excellent Field Guide to safeguard VMware disk files with Tivoli TSM under VMware GSX (Linux) and VMware ESX for free download.

In addition to discussing general security issues it also address special tuning tips and useful information on the configuration. Absolutely marvelous!
This Field Guide, can be downloaded from here

Update: A new guide of how to setup TSM to backup VMware ESX using VMware Consolidated backup can be found at:

IBM Tivoli Storage Manager & VMware Consiledated Backup (VCB)

I hope these guides help you backup your VMware enviornment with VMware. If you need any more help, or just want to say thank you please leave it in the comment below.