v1.9 Pending Release Notes

Breaking Changes

The mds liveness and startup probes are now configured by the filesystem CR instead of the cluster CR. To apply the mds probes, they need to be specified in the filesystem CR. See the filesystem CR doc for more details. See #9550
In the helm charts, all Ceph components now have default values for the pod resources. The values can be modified or removed in values.yaml depending on cluster requirements.
Prometheus rules are installed by the helm chart. If you were relying on the cephcluster setting monitoring.enabled to create the prometheus rules, they instead need to be enabled by setting monitoring.createPrometheusRules in the helm chart values.
The region field for OBC Storage class is ignored, the RGW server always works with s3 client using us-east-1 as region.

The number of mgr daemons for example clusters is increased to 2 from 1, resulting in a standby mgr daemon. If the active mgr goes down, Ceph will update the passive mgr to be active, and rook will update all the services with the label app=rook-ceph-mgr to direct traffic to the new active mgr.
Network encryption is configurable with settings in the CephCluster CR. Requires the 5.11 kernel or newer.
Network compression is configurable with settings in the CephCluster CR. Requires Ceph Quincy (v17) or newer.
Add support for custom ceph.conf for csi pods. See #9567
Added and updated many Ceph prometheus rules, picked up from the ceph repo