This is the second release candidate for Umbrella. All community feedback is welcome. Packages built for: - Ubuntu 22.04 - Ubuntu 24.04 - CentOS 9 - Rocky Linux 10 - Debian 12 (Bookworm) - Debian 13 (Trixie) Containers are built on a Rocky 10 base image, available at: https://quay.io/repository/ceph/ceph?tab=tags Please note: the full draft release notes for v21.2.0 are available at https://github.com/ceph/ceph/pull/70240 Notable changes from 21.1.0, the first release candidate: - Fixes for CVE-2025-30156, CVE-2026-39944,CVE-2026-50152, and CVE-2026-54330 included. (Please see upgrade notes for v20.2.4/v19.2.6.) - MGR: The default values of ``mon_target_pg_per_osd`` and ``mon_max_pg_per_osd`` have been increased from 100 and 250 to 200 and 500, respectively. These values enhance the PG autoscaler's ability to calculate reasonable ``pg_num`` values for pools under its control. These in turn increase parallelism and performance, and improve the ``balancer`` module's ability to acheive uniform OSD utilization. [This concomitant PR](https://github.com/ceph/ceph/pull/67694) ensures that upgrades are not delayed or disrupted by PG splitting as a result of this change. Clusters with effective ``bluestore_osd_memory_target`` values smaller than the default 4GiB may wish to explicitly set the previous default values in the central config store before upgrading. This will reduce the potential for increased memory starvation. Clusters with SSDs split into more than two OSDs may also wish to pin their current values in advance, or redeploy those SSDs with at most two OSDs per. - RGW: In multisite deployments, zone endpoints configured in the zonegroup (e.g. ``https://zone-a.example.com``) can now be resolved to all IP addresses returned by DNS, with inter-zone traffic distributed across them using round-robin and per-IP health tracking. This enables DNS-based service discovery for inter-zone traffic without an external load balancer. This feature is disabled by default: to opt in, set ``rgw_rest_conn_connect_to_resolved_ips = true``. The per-IP retry-after-failure timeout is controlled by ``rgw_rest_conn_ip_fail_timeout_secs`` (default: 2 seconds). Deployments that work around libcurl's single-address behavior by repeating the same endpoint multiple times in zone configuration should review that setup before enabling, as round-robin distribution makes such duplication unnecessary. - RGW: The rgw_gc_max_deferred and rgw_gc_max_deferred_entries_size options have been removed, as they did not do anything. - Updated the default for rgw_gc_max_queue_size to account for the extra space from removing rgw_gc_max_deferred_entries_size. - RGW: The default value of ``rgw_thread_pool_size`` has been reduced from 512 to 128. Benchmarks showed that the lower thread count improves throughput and reduces latency on NVMe and HDD based environments. Users with specific workload requirements can tune this value; see also ``rgw_max_concurrent_requests``. - CephFS Mirroring: The ``fs mirror peer status`` admin socket command reports additional per-directory sync metrics (sync mode, throughput, crawl and data-sync queue timing, bytes/files progress, and ETA). Output is grouped under ``metrics/<mirrored-dir-path>/peer/<peer-uuid>``. For more information, see https://tracker.ceph.com/issues/73453 - CephFS Mirroring: Per-directory snapshot sync progress is exposed as labeled perf counters in the ``cephfs_mirror_directory`` group (``counter dump`` on the mirror daemon admin socket, exportable via ``ceph-exporter``). Counters mirror ``fs mirror peer status`` fields (directory state, current sync, last sync, and snap summary) and are labeled by peer UUID and mirrored directory path. See https://tracker.ceph.com/issues/73457 - RADOS: PG autoscaler allows overlapping roots. Each root receives a PG target based on its OSDs, with OSDs shared across multiple roots contributing proportionally less to each root's allocation. - CephFS Mirroring: Introduced snapshot checkpoints feature that allows users to mark specific snapshots as important milestones and track their replication status to remote sites. Checkpoints automatically detect if a snapshot has already been synced and provide visibility into disaster recovery readiness. The feature includes four new CLI commands: ``ceph fs snapshot mirror checkpoint add`` to mark a snapshot, ``ceph fs snapshot mirror checkpoint now`` to checkpoint the latest snapshot, ``ceph fs snapshot mirror checkpoint ls`` to list all checkpoints with their status (created/complete/failed), and ``ceph fs snapshot mirror checkpoint remove`` to remove a checkpoint. Checkpoint metadata is persistent across daemon restarts. This feature is useful for compliance auditing, application consistency verification, and SLA tracking. For more information, see https://tracker.ceph.com/issues/73454 - RBD: It's possible to specify source cluster's ``mon_host`` and ``key`` for ``native`` format migration via the migration spec now. This eliminates the dependency on ``<cluster-name>.conf`` file in a known location which is rather rigid and also challenging to disseminate in some environments. The key can be embedded in the migration spec or just referenced from there while stored in the MON config-key store. - RBD: It's possible to specify source cluster's ``mon_host`` and ``key`` for ``native`` format migration via the migration spec now. This eliminates the dependency on ``<cluster-name>.conf`` file in a known location which is rather rigid and also challenging to disseminate in some environments. The key can be embedded in the migration spec or just referenced from there while stored in the MON config-key store. - RBD: It's possible to specify source cluster's ``mon_host`` and ``key`` for ``native`` format migration via the migration spec now. This eliminates the dependency on ``<cluster-name>.conf`` file in a known location which is rather rigid and also challenging to disseminate in some environments. The key can be embedded in the migration spec or just referenced from there while stored in the MON config-key store. - Git at git://github.com/ceph/ceph.git - Tarball at https://download.ceph.com/tarballs/ceph-21.1.1.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: 815bc6b6f9b4e0fd98daed552ec8e7123a0a8f84 - Distribution matrix: https://docs.ceph.com/en/latest/start/os-recommendations/ -- Patrick Donnelly, Ph.D. He / Him / His Red Hat Partner Engineer IBM, Inc. GPG: 19F28A586F808C2402351B93C3301A3E258DD79D