Update notes¶
Although MOSK 24.3.1 is classified as a patch release, as a cloud operator, you will be performing a major update regardless of the upgrade path: whether you are upgrading from patch 24.2.5 or major version 24.3. This is because of the Mirantis Container Runtime update to 23.0.15.
This section describes the specific actions you need to complete to accurately plan and successfully perform the update. Consider this information as a supplement to the generic update procedure published in Operations Guide: Update a MOSK cluster.
Cluster update schema¶
You can update to the 24.3.1 version from the following cluster versions:
24.3 (released on October 16, 2024)
24.2.5 (released on December 09, 2024)
For the detailed cluster update schema, refer to Managed cluster update schema.
Optional migration of container runtime from Docker to containerd¶
MOSK 24.3.1 enables optional migration of container runtime from Docker to containerd. Usage of containerd introduces a major enhancement for cloud workloads running on top of MOSK, as it helps minimize the network connectivity downtime caused by underlying infrastructure updates.
To minimize the number of required maintenance windows, Mirantis recommends that cloud operators switch to the containerd runtime on the nodes simultaneously with their upgrade to Ubuntu 22.04 if the Ubuntu upgrade has not been completed before.
Note
Migration from Docker to containerd will become mandatory in MOSK 25.1.
Required action
Update impact and maintenance windows planning¶
The following table provides details on the update impact on a MOSK cluster.
Updated component |
Impact on cloud users |
Impact on cloud workloads |
|---|---|---|
OpenStack and Tungsten Fabric |
|
Open vSwitch networking - interruption of the North-South connectivity, depending on the type of virtual routers used by a workload:
Tungsten Fabric networking - no impact |
Ceph |
~1% of read operations on object storage API may fail |
IO performance degradation for Ceph-backed virtual storage devices |
Host OS components |
No impact |
Instance network connectivity interruption up to 5 minutes |
Host OS kernel |
No impact |
Restart of instances due to the hypervisor reboot 0 |
- 0
Host operating system needs to be rebooted for the kernel update to be applied. Configure live-migration of workloads to avoid the impact on the instances running on a host.
To properly plan the update maintenance window, use the following documentation:
Known issues during the update¶
Before updating the cluster, be sure to review the potential issues that may arise during the process and the recommended solutions to address them, as outlined in Update known issues.
Post-update actions¶
Upgrade Ubuntu to 22.04 and migrate to containerd runtime¶
MOSK 24.3 release series is the last release series to support Ubuntu 20.04 as the host operating system. Ubuntu 20.04 reaches end-of-life in April 2025. Therefore, Mirantis encourages all MOSK users to upgrade their clusters to Ubuntu 22.04 as soon as possible after getting to the 24.3 series. A host operating system upgrade requires reboot of the nodes and can be performed in small batches.
Also, MOSK 24.3.1 introduces the new container runtime for the underlying Kubernetes cluster - containerd. The migration from Docker to containerd in 24.3.1 is optional and requires node cordoning and draining. Therefore, if you decide to start using containerd and have not yet upgraded to Ubuntu 22.04, Mirantis highly recommends that these two changes be applied simultaneously to every node to minimize downtime for cloud workloads and users:
Warning
Update of management or MOSK clusters running Ubuntu 20.04 or Docker runtime will not be possible in the following product series.
Caution
Usage of third-party software, which is not part of Mirantis-supported configurations, for example, the use of custom DPDK modules, may block upgrade of an operating system distribution. Users are fully responsible for ensuring the compatibility of such custom components with the latest supported Ubuntu version.