It is important to review the Install/Upgrade Notes below before upgrading to any Rancher version.
In Rancher v2.6.4, the cluster-api module has been upgraded from v0.4.4 to v1.0.2 in which the apiVersion of CAPI CRDs are upgraded from
cluster.x-k8s.io/v1beta1. This has the effect of causing rollbacks from Rancher v2.6.4 to any previous version of Rancher v2.6.x to fail because the previous version the CRDs needed to roll back are no longer available in v1beta1. To avoid this, the Rancher resource cleanup script should be run before the restore or rollback is attempted. This script can be found in the rancherlabs/support-tools repo and the usage of the script can be found in the backup-restore operator docs . See also #36803 for more details.
Note: Rancher v2.6.6 is a mirror release of v2.6.5 with the addition of the bug fix below.**
- A major performance issue was occurring when Rancher was attempting to control large volumes of traffic from downstream clusters. This mechanism was not handling disconnects properly and would result in indefinite locks. See #37250.