[ceph-users] postgresql vs ceph, fsync

We are evaluating pros and cons of running postgresql backed by ceph. We know that running pg on dedicated physical hw is highly recommended, but we've got our reasons. So to the question: What could happen if we switch fsync to off on postgre backed by ceph? The increase of perfomance is huge, which is the reason we are considering it. Ceph pool is running on osds connected to controllers with batteries so we could mitigate power losses. What happens when an osd run out of space? Are there other considerations?