Migrating to a new Ubuntu version

To migrate your worker nodes to a new Ubuntu version, run a command to specify the new version for a worker pool. Then, update the individual worker nodes in the pool.

Default operating system by cluster version

Ubuntu 24 is the default operating system for all supported cluster versions. A worker pool's operating system does not automatically change when you upgrade a cluster.

Ubuntu 24 limitations

Portworx does not currently support Ubuntu 24. Do not create or migrate to Ubuntu 24 worker pools if you need to use Portworx.

Migration steps

Migrate your worker nodes to use Ubuntu 24. These steps apply to all supported cluster versions.

For Ubuntu 24, the /tmp directory is a separate partition that has the nosuid, noexec, and nodev options set. If your apps install to and run scripts or binaries under the /tmp directory, they might fail. You can use the /var/tmp directory instead of the /tmp directory to run temporary scripts or binaries.

Review your worker pool operating systems to determine which pools you need to migrate.
```
ibmcloud ks worker-pools -c CLUSTER
```

Specify the new Ubuntu version for the worker pool.

ibmcloud ks worker-pool operating-system set --cluster CLUSTER --worker-pool POOL --operating-system UBUNTU_24_64

Update each worker node in the worker pool by running the ibmcloud ks worker update or ibmcloud ks worker replace command.

Make sure you have enough worker nodes to support your workload while you update or replace the relevant worker nodes. For more information, see Updating VPC worker nodes or Updating classic worker nodes.

Example command to update Classic worker nodes.
```
ibmcloud ks worker update --cluster CLUSTER --worker WORKER1_ID [--worker WORKER2_ID] 
```
Example command to update VPC worker nodes.
```
ibmcloud ks worker replace --cluster CLUSTER --worker WORKER_ID
```
Get the details for your worker pool and workers. In the output, verify that your worker nodes run the new Ubuntu version.

Get the details for a worker pool.
```
ibmcloud ks worker-pools -c CLUSTER
```
Get the details for a worker node.
```
ibmcloud ks worker get --cluster CLUSTER --worker WORKER_NODE_ID 
```