[CentOS] who uses Lustre in production with virtual machines?

I'm considering setting up a Lustre cluster system for our XEN virtual machines as shared storage, mainly for high availability on our XEN VPS servers.

Does anyone use Lustre in a production environment? What is your opinions / experiences with it?

One of the main reasons I'm looking at using Lustre is that we have a few older machines, of different specs that I want to use for storage purposes. i.e. I don't want to use proprietary, or matching hardware if I don't want to. Many of these machines are still in good standing and of good spec (3.2Ghz PIV + HT & 4GB RAM, Core2Duo + 4GB RAM, single XEON + 4GB RAM, dual core Atoms, etc) Will this work?