Is a virtual NAS/Webserver setup like this possible?

Here is how I want to setup my home server to use as a NAS and let me bring up/down webservers for developing on.

One 300GB disk to use for running servers. A two 3TB disk mirror for file back up and virtual server backup off the server drive.

I'm having trouble getting the two disk mirror running. I have used both xenserver and ESXi, but I'm not sure how to get direct disk access or how to set up mirroring in the software.

I want to use software mirroring for the data drive so in the case of an emergency I can pull the drive and copy the data off without any special raid hardware.

So basically I need help with a software drive mirror on a xenserver or ESXi server.