[Wlug] Ceph

Has anyone here used ceph? I'm debating using it in a production cluster and would like input, alternatives, etc. Requirements: High availability, scales dynamically, fault tolerant, NO CODE CHANGES ( must appear as a posix compatible file system and be able to be mounted as such) nodes must be able to be added to the cluster at will. Prefer multi to multi copy for recovery (removed slow disk recovery bottleneck)