Feature highlights:

- RADOS/OSD: New Optimized ("Fast") Erasure Coding I/O path (direct/sync reads, OMAP support, deep scrub); mon RocksDB backup/restore; stretch cluster improvements; mClock scheduler refactor; continued Crimson/Seastore EC and perf work.
- RGW: Full object dedup (tech preview); bucket logging; cloud restore from Glacier/tape; AES-256-GCM encryption + security fixes; expanded IAM/Account and STS/OIDC support.
- Dashboard: Large-scale migration to IBM Carbon design; expanded NVMe/TCP management; SMB cluster support; OAuth2 SSO; Angular 19.
- cephadm/Orchestrator: New unified certmgr for TLS cert management; SMB/Samba managed service; expanded NVMe-oF gateway spec; new hardware monitoring (Atollon BMCs); NFS-Ganesha active-active mode.
- CephFS/MDS: FSCrypt client-side encryption; multi-threaded cephfs-mirror; new python bindings; subvolume improvements.
- ceph-volume: Migrated to dataclasses + udev-based device detection (perf/reliability); seastore OSD support.
- Build/Packaging/QA: Ubuntu 24.04 (Noble) and Rocky Linux 10 support added; the Ceph container's base OS image has changed to rockylinux:10; CMake 3.22.1+/CMake-4; C++23.  
 
- Git at git://github.com/ceph/ceph.git
- Tarball at https://download.ceph.com/tarballs/ceph-21.1.0.tar.gz
- Containers at https://quay.io/repository/ceph/ceph
- For packages, see https://docs.ceph.com/en/latest/install/get-packages/
- Release git sha1: f7eb5f7c8097648828a6b31f4590c3ee3661c95a