This is the first release candidate for Tentacle. Ubuntu 22.04, 24.04 and CentOS 9 were built for this RC0 Feature highlights: * RADOS: New features include long expected performance optimizations (FastEC) for EC pools, including partial reads and partial writes. Users can also expect to see BlueStore improvements such as compression and a new, faster WAL (write-ahead-log). Additional improvements include switching all components to the faster OMAP iteration interface, bypassable ceph_assert()s, fixed mclock bugs and configuration defaults, and testing improvements for dencoding verification. * MGR: Highlights include the ability to force-disable always-on modules and the removal of the restful and zabbix modules (both deprecated since 2020). Note that the dashboard module's richer and better-maintained RESTful API can be used as an alternative to the restful module, and the prometheus module can be used as an alternative monitoring solution for zabbix. * RGW: Multiple fixes: Lua scripts will not run against health checks, properly quoted ETag values returned by S3 CopyPart, PostObject and CompleteMultipartUpload responses. * RGW: IAM policy evaluation now supports conditions ArnEquals and ArnLike, along with their Not and IfExists variants. * RBD: New live migration features: RBD images can now be instantly imported from another Ceph cluster (native format) or from a wide variety of external sources/formats with the help of the new NBD stream and an appropriately capable NBD server such as `qemu-nbd`. Also added support for RBD namespace remapping while mirroring between Ceph clusters, new `rbd group info` and `rbd group snap info` commands and enhanced `rbd group snap ls` command. `rbd device map` command now defaults to msgr2. * CephFS: Directories may now be configured with case-insensitive or normalized directory entry names. This is an inheritable configuration making it apply to an entire directory tree. For more information, see https://docs.ceph.com/en/latest/cephfs/charmap/ * CephFS: Modifying the FS setting variable "max_mds" when a cluster is unhealthy now requires users to pass the confirmation flag (--yes-i-really-mean-it). This has been added as a precaution to tell the users that modifying "max_mds" may not help with troubleshooting or recovery effort. Instead, it might further destabilize the cluster. * CephFS: EOPNOTSUPP (Operation not supported ) is now returned by the CephFS fuse client for `fallocate` for the default case (i.e. mode == 0) since CephFS does not support disk space reservation. The only flags supported are `FALLOC_FL_KEEP_SIZE` and `FALLOC_FL_PUNCH_HOLE`. * Dashboard: Added support for NVMe/TCP (gateway groups, multiple namespaces), multi-cluster management, oAuth2 integration, and enhanced RGW/SMB features including multi-site automation, tiering, policies, lifecycles, notifications, and granular replication. * Git at git://github.com/ceph/ceph.git * Tarball at https://download.ceph.com/tarballs/ceph-20.1.0.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: 010a3ad647c9962d47812a66ad6feda26ab28aa4