longhorn/docs/upgrade.md

Upgrade

Here we cover how to upgrade to Longhorn v0.3 from all previous releases.

Backup Existing Volumes

It's recommended to create a recent backup of every volume to the backupstore before upgrade.

If you don't have a on-cluster backupstore already, create one. Here we'll use NFS for example.

1. Execute following command to create the backupstore

kubectl apply -f https://raw.githubusercontent.com/rancher/longhorn/v0.3-rc/deploy/backupstores/nfs-backupstore.yaml

2. On Longhorn UI Settings page, set Backup Target to nfs://longhorn-test-nfs-svc.default:/opt/backupstore and click Save.

Navigate to each volume detail page and click Take Snapshot (it's recommended to run sync in the host command line before Take Snapshot). Click the new snapshot and click Backup. Wait for the new backup to show up in the volume's backup list before continuing.

Check For Issues

Make sure no volume is in degraded or faulted state. Wait for degraded volumes to heal and delete/salvage faulted volumes before proceeding.

Detach Volumes

Shutdown all Kubernetes Pods using Longhorn volumes in order to detach the volumes. The easiest way to achieve this is by deleting all workloads and recreate them later after upgrade. If this is not desirable, some workloads may be suspended. We will cover how each workload can be modified to shut down its pods.

Deployment

Edit the deployment with kubectl edit deploy/<name>. Set .spec.replicas to 0.

StatefulSet

Edit the statefulset with kubectl edit statefulset/<name>. Set .spec.replicas to 0.

DaemonSet

There is no way to suspend this workload. Delete the daemonset with kubectl delete ds/<name>.

Pod

Delete the pod with kubectl delete pod/<name>. There is no way to suspend a pod not managed by a workload controller.

CronJob

Edit the cronjob with kubectl edit cronjob/<name>. Set .spec.suspend to true. Wait for any currently executing jobs to complete, or terminate them by deleting relevant pods.

Job

Consider allowing the single-run job to complete. Otherwise, delete the job with kubectl delete job/<name>.

ReplicaSet

Edit the replicaset with kubectl edit replicaset/<name>. Set .spec.replicas to 0.

ReplicationController

Edit the replicationcontroller with kubectl edit rc/<name>. Set .spec.replicas to 0.

Wait for the volumes using by the Kubernetes to complete detaching.

Then detach all remaining volumes from Longhorn UI. These volumes were most likely created and attached outside of Kubernetes via Longhorn UI or REST API.

Uninstall the Old Version of Longhorn

Make note of BackupTarget on the Setting page. You will need to manually set BackupTarget after upgrading from either v0.1 or v0.2.

Delete Longhorn components.

For Longhorn v0.1 (most likely installed using Longhorn App in Rancher 2.0):

kubectl delete -f https://raw.githubusercontent.com/llparse/longhorn/v0.1/deploy/uninstall-for-upgrade.yaml

For Longhorn v0.2:

kubectl delete -f https://raw.githubusercontent.com/rancher/longhorn/v0.2/deploy/uninstall-for-upgrade.yaml

If both commands returned Not found for all components, Longhorn is probably deployed in a different namespace. Determine which namespace is in use and adjust NAMESPACE here accordingly:

NAMESPACE=<some_longhorn_namespace>
curl -sSfL https://raw.githubusercontent.com/rancher/longhorn/v0.1/deploy/uninstall-for-upgrade.yaml|sed "s#^\( *\)namespace: longhorn#\1namespace: ${NAMESPACE}#g" > longhorn.yaml
kubectl delete -f longhorn.yaml

Backup Longhorn System

We're going to backup Longhorn CRD yaml to local directory, so we can restore or inspect them later.

v0.1

User must backup the CRDs for v0.1 because we will change the default deploying namespace for Longhorn. Check your backups to make sure Longhorn was running in namespace longhorn, otherwise change the value of NAMESPACE below.

NAMESPACE=longhorn
kubectl -n ${NAMESPACE} get volumes.longhorn.rancher.io -o yaml > longhorn-v0.1-backup-volumes.yaml
kubectl -n ${NAMESPACE} get engines.longhorn.rancher.io -o yaml > longhorn-v0.1-backup-engines.yaml
kubectl -n ${NAMESPACE} get replicas.longhorn.rancher.io -o yaml > longhorn-v0.1-backup-replicas.yaml
kubectl -n ${NAMESPACE} get settings.longhorn.rancher.io -o yaml > longhorn-v0.1-backup-settings.yaml

v0.2

Check your backups to make sure Longhorn was running in namespace longhorn-system, otherwise change the value of NAMESPACE below.

NAMESPACE=longhorn-system
kubectl -n ${NAMESPACE} get volumes.longhorn.rancher.io -o yaml > longhorn-v0.2-backup-volumes.yaml
kubectl -n ${NAMESPACE} get engines.longhorn.rancher.io -o yaml > longhorn-v0.2-backup-engines.yaml
kubectl -n ${NAMESPACE} get replicas.longhorn.rancher.io -o yaml > longhorn-v0.2-backup-replicas.yaml
kubectl -n ${NAMESPACE} get settings.longhorn.rancher.io -o yaml > longhorn-v0.2-backup-settings.yaml

Delete CRDs in Different Namespace

This is only required for Rancher users running Longhorn App v0.1. Delete all CRDs from your namespace which is longhorn by default.

NAMESPACE=longhorn
kubectl -n ${NAMESPACE} get volumes.longhorn.rancher.io -o yaml | sed "s/\- longhorn.rancher.io//g" | kubectl apply -f -
kubectl -n ${NAMESPACE} get engines.longhorn.rancher.io -o yaml | sed "s/\- longhorn.rancher.io//g" | kubectl apply -f -
kubectl -n ${NAMESPACE} get replicas.longhorn.rancher.io -o yaml | sed "s/\- longhorn.rancher.io//g" | kubectl apply -f -
kubectl -n ${NAMESPACE} get settings.longhorn.rancher.io -o yaml | sed "s/\- longhorn.rancher.io//g" | kubectl apply -f -
kubectl -n ${NAMESPACE} delete volumes.longhorn.rancher.io --all
kubectl -n ${NAMESPACE} delete engines.longhorn.rancher.io --all
kubectl -n ${NAMESPACE} delete replicas.longhorn.rancher.io --all
kubectl -n ${NAMESPACE} delete settings.longhorn.rancher.io --all

Install Longhorn v0.3

Installed with Longhorn App v0.1 in Rancher 2.x

For Rancher users who are running Longhorn v0.1, do not click the upgrade button in the Rancher App.

1. Delete the Longhorn App from Catalog Apps screen in Rancher UI.
2. Launch Longhorn App template version 0.3.0.
3. Restore Longhorn System data. This step is required for Rancher users running Longhorn App v0.1. Don't change the NAMESPACE variable below, since the newly installed Longhorn system will be installed in the longhorn-system namespace.

NAMESPACE=longhorn-system
sed "s#^\( *\)namespace: .*#\1namespace: ${NAMESPACE}#g" longhorn-v0.1-backup-settings.yaml | kubectl apply -f -
sed "s#^\( *\)namespace: .*#\1namespace: ${NAMESPACE}#g" longhorn-v0.1-backup-replicas.yaml | kubectl apply -f -
sed "s#^\( *\)namespace: .*#\1namespace: ${NAMESPACE}#g" longhorn-v0.1-backup-engines.yaml | kubectl apply -f -
sed "s#^\( *\)namespace: .*#\1namespace: ${NAMESPACE}#g" longhorn-v0.1-backup-volumes.yaml | kubectl apply -f -

Installed without using Longhorn App v0.1

For Longhorn v0.2 users who are not using Rancher, follow the official Longhorn Deployment instructions.

Access UI and Set BackupTarget

Wait until the longhorn-ui and longhorn-manager pods are Running:

kubectl -n longhorn-system get pod -w

Access the UI.

On Setting > General, set Backup Target to the backup target used in the previous version. In our example, this is nfs://longhorn-test-nfs-svc.default:/opt/backupstore.

Upgrade Engine Images

Ensure all volumes are detached. If any are still attached, detach them now and wait until they are in Detached state.

Select all the volumes using batch selection. Click batch operation button Upgrade Engine, choose the only engine image available in the list. It's the default engine shipped with the manager for this release.

Attach Volumes

Now we will resume all workloads by reversing the changes we made to detach the volumes. Any volume not part of a K8s workload or pod must be attached manually.

Note

Upgrade is always tricky. Keeping recent backups for volumes is critical. If anything goes wrong, you can restore the volume using the backup.

If you have any issues, please report it at https://github.com/rancher/longhorn/issues and include your backup yaml files as well as manager logs.