Does anyone using dm-cache?

Hi,

Has, or does, anyone use dm-cache - specifically for caching SAN based storage locally?

I’m looking for a way to speed up SAN based storage on a CentOS 5.6 + XEN Hypervisor which uses iSCSI mounted SAN storage. dm-cache seems like it do the trick, but I’ve never heard of it before until someone mentioned it in another mailing list. A quick search on google didn’t really give me much in terms of actual user experience.

Does anyone use it?
Any feedback? Pitfalls? Success stories?

I’m referring to this: https://github.com/mingzhao/dm-cache/blob/5670b91bc7c412885339f11fcf794a70c26da879/README