From v0.3.x

From Longhorn deployment yaml

If you didn’t change any configuration during Longhorn v0.3.0 installation, follow the official Longhorn Deployment instructions to upgrade.

Otherwise you will need to download the yaml file from the official Longhorn Deployment instructions, modify it to your need, then use kubectl --kubeconfig=kube_configxxx.yml apply -f to upgrade.

From Longhorn App (Rancher Catalog App)

On Rancher UI, navigate to the Catalog Apps screen and click the Upgrade available button. Do not change any of the settings. Do not change any of the settings right now. Click Upgrade.

Access Longhorn UI. Periodically refresh the page until the version in the bottom left corner of the screen changes. Wait until websocket indicators in bottom right corner of the screen turn solid green. Navigate to Setting> Engine Image and wait until the new Engine Image is Ready.