I’m running the latest update, and I noticed that ceph (or ceph-libs) which is in the AUR is being built.
While it is possible I installed ceph as a dependency of some AUR app I had, briefly, installed on my system, I can’t otherwise think of any reason why I would have installed it.
Given, it is not in the Official Repositories, I can’t think of any reason for it being installed, in the first place, given it appears to be designed for very large filesystems, and I don’t have any.