why
why would you want to risk storage by running workloads on a storage system? It's not like your going to benefit from ultra low latency on such a system it's distributed object storage. Even if you did benefit, spend the extra $ and get dedicated compute hardware, keep them separate.
my VAR has latched onto the idea of Cleversafe back end + Avere front end(NAS + tiering/caching) which seems to be an interesting combination. I have warned him against Ceph, not mature enough for most customers out there. (Not sure how much better Cleversafe is but they do seem to be the market leader so that says something at least). I believe Ceph has NAS as well but that's another thing I wouldn't put much trust in at this stage of their game.
I'm not in the market for such a system and don't imagine that changing in the next 2-3 years anyway.