Detecting Ceph LARGE_OMAP_OBJECTS Before Deep Scrub Finds It

LARGE_OMAP_OBJECTS has an annoying property: it tells you about a problem that started days ago. An RGW bucket index shard, a CephFS metadata object, or an application object built on librados grows past the threshold, and nothing in ceph health changes until a deep scrub happens to walk that PG. With the default deep-scrub interval of seven days,...