Relokator

Relokator makes it easy to move data from StorageClass to another, for example allowing you to migrate a zonal PV to a regional PV.

Installation

If you have Go installed and enabled Go modules (GO111MODULE="on"):

$> go get github.com/ninech/relokator
$> relokator -h

Or with Docker (need to mount your kubeconfig credentials into the container):

docker run -v ~/.kube:/.kube ninech/relokator -h

Usage

Before running this tool, make sure you have backed up your data!

There is downtime involved with the migration! We recommend running relokator on a per-PVC basis and migrate your PVCs one by one. relokator will print the PVCs that will be migrated before starting the migration and will ask for confirmation.

relokator will wait until no pod has the PVC mounted anymore. It:

Scales down Deployments, ReplicaSets and StatefulSets to 0 (and scale it up again when it's done)
Suspends CronJobs so that they will not interfere
Waits for Jobs (or already running CronJobs) to complete

It cannot handle DaemonSets. If you have a DaemonSet that mounts a PVC you want to migrate, you will need to scale it down manually somehow.

The new PVC (the target of the migration) will have some annotations set for Argo CD in order to ensure that it will not be reconciled and changed again. After the migration is complete, get the new manifest for your PVC (kubectl get pvc <name> -o yaml), remove the annotations

argocd.argoproj.io/sync-options: "Prune=false"
argocd.argoproj.io/compare-options: "IgnoreExtraneous"

and add the new manifest to your git. This will cause ArgoCD to reconcile the PVC again.

Relokator is written in a way that allows it to be stopped and restarted flexibly. This means if Relokator encounters an error, it is possible to retry by running the same command again.

Example Usage

To migrate the PVC app-persistent in namespace my-super-app from the source StorageClass nfs to destination StorageClass filestore:

./relokator -namespace my-super-app -pvc app-persistent \
            -target-class "filestore" -source-class "nfs"

Reporting Issues

If you are opening an issue, please ensure that you have the latest version of relokator installed and supply the output with -loglevel debug enabled.