Chapter 4. Ceph OSDs

Enhancements to Ceph OSDs include adding new erasure-code regression tests, adding use-after-free code in cache tiering code, handling EC + primary affinity misdirected op checks properly, and mounting XFS with inode64 by default.

Erasure-coding and cache tiering are tech previews only and are not supported for production clusters.

Ceph OSD journals have enhancements to direct-io shutdown, journal dump, snap trimming performance, and snapdir handling on cache eviction.

Peering enhancements include clearing rollback PG metadata on PG deletion, addressing occasional stalls during peering or activation, and displaying past_interval values correctly.

Backfill enhancements include making backfill reservation denial handling more robust, fixing full OSD checks during backfill, and removing bad backfill assertions for mixed-version clusters.

Additional enhancements include cleanly aborting set-alloc-hint operations during upgrade; cancelling callback on blacklisted watchers; not aborting deep scrub if hinfo is missing; parsing ioprio properly; processing admin socket dump_ops_in_flight properly; handling map gaps in map advance code; handling undefined CRUSH results in interval check; including shard in JSON dump of ghobject; and, fixing invalid memory reference in log trimming.