[keeperofdakeys]

Ceph overheads aren't that large for a small cluster, but they grow as you add more hosts, drives, and more storage. Probably the main gotcha is that you're (ideally) writing your data three times on different machines, which is going to lead to a large overhead compared with local storage.

Most resource requirements for Ceph assume you're going for a decently sized cluster, not something homelab sized.