Best way to back up a 2tb Disk (vm) with millions of small files

Best way to back up a 2tb Disk (vm) with millions of small files

Like the title says I have a 2TB vm running on VMware 5.5 (virtual vCenter as well)with millions of small files that I need to back up to tape.
I have DP9, MSL4048's, D2D library
The VMcluster is on a fiber 3Par 7200
The Cell Manager, tape liraries and D2D are all on the same fiber and zoned together.

I would only need to resotre the whole VM, never individual files.
Right now it takes about 10hours to back it up. I have tried using a agent in the server as well as doing a virtual backup, both take roughly the same time.
Im interested in your thoughts for the best way to back up, I am open to options including different hardware, software, and hardware configurations, you name it.

Thanks so much for your time, this has been an on going issue for me for way too long!