Create and use local snapshots

This document will show you how to create snapshots of Portworx volumes and how you can clone those snapshots to use them in pods.

The suggested way to manage snapshots on Kuberenetes is to use Stork. If you are looking to create Portworx snapshots using PVC annotations, you will find instructions here.

Prerequisites

Install Stork

This requires that you already have Stork installed and running on your Kubernetes cluster. If you fetched the Portworx specs from the Portworx spec generator in PX-Central and used the default options, Stork is already installed.

Create snapshots

With local snapshots, you can either snapshot individual PVCs one by one or snapshot a group of PVCs by using a label selector.

Restore snapshots

Once you’ve created a snapshot, you can restore it to a new PVC or the original PVC.

Restore a local snapshot to a new PVC

When you install Stork, it also creates a storage class called stork-snapshot-sc. This storage class can be used to create PVCs from snapshots.

To create a PVC from a snapshot, add the snapshot.alpha.kubernetes.io/snapshot annotation to refer to the snapshot name. If the snapshot exists in another namespace, you should specify the snapshot namespace with the stork.libopenstorage.org/snapshot-source-namespace annotation in the PVC.

The Retain policy is important if you need to keep the volume in place, even after removing the Kubernetes objects from a cluster.

NOTE:

As shown in the following example, the storageClassName should be the Stork StorageClass stork-snapshot-sc.
When using this storage class the PVC is creating with delete as Retain policy. However, if the source PVC is having the policy as retain, then this will not be inherited to the restored PVC. After the restore, you should manually verify the retain policy and change it if needed.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-snap-clone
  annotations:
    snapshot.alpha.kubernetes.io/snapshot: mysql-snapshot
spec:
  accessModes:
     - ReadWriteOnce
  storageClassName: stork-snapshot-sc
  resources:
    requests:
      storage: 2Gi

Once you apply the above spec, you will see a PVC created by Stork. This PVC will be backed by a Portworx volume clone of the snapshot created above.

kubectl get pvc

NAMESPACE   NAME                                   STATUS    VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS                AGE
default     mysql-data                             Bound     pvc-f782bf5c-20e7-11e8-931d-0214683e8447   2Gi        RWO            px-mysql-sc                 2d
default     mysql-snap-clone                       Bound     pvc-05d3ce48-2280-11e8-98cc-0214683e8447   2Gi        RWO            stork-snapshot-sc           2s

Restore a local snapshot to the original PVC

When you perform an in-place restore to a PVC, Stork takes the pods using that PVC offline, restores the volume from the snapshot, then brings the pods back online.

NOTE: In-place restore using VolumeSnapshotRestore works only for applications deployed using the stork scheduler. If you’re not using the Stork scheduler, Portworx displays the following error when describing the VolumeSnapshotRestore resource:

Events:
  Type     Reason  Age               From   Message
  ----     ------  ----              ----   -------
  Warning  Failed  5s (x2 over 15s)  stork  application not scheduled by stork scheduler

Create a VolumeSnapshotRestore YAML file specifying the following:
- apiVersion as stork.libopenstorage.org/v1alpha1
- kind as VolumeSnapshotRestore
- metadata.name with the name of the object that performs the restore
- metadata.namespace with the name of the target namespace
- spec.sourceName with the name of the snapshot you want to restore
- spec.sourceNamespace with the namespace in which the snapshot resides
The following example restores data from a snapshot called mysql-snapshot which was created in the mysql-snap-restore-splocal namespace to a PVC called mysql-snap-inrestore in the default namespace:
```
 apiVersion: stork.libopenstorage.org/v1alpha1
 kind: VolumeSnapshotRestore
 metadata:
   name: mysql-snap-inrestore
   namespace: default
 spec:
   sourceName: mysql-snapshot
   sourceNamespace: mysql-snap-restore-splocal
```
Place the spec into a file called mysql-cloud-snapshot-restore.yaml and apply it:
```
 kubectl apply -f mysql-cloud-snapshot-restore.yaml
```

You can enter the following command to see the status of the restore process:

 storkctl get volumesnapshotrestore

 NAME                   SOURCE-SNAPSHOT   SOURCE-SNAPSHOT-NAMESPACE   STATUS          VOLUMES   CREATED
 mysql-snap-inrestore   mysql-snapshot    default                     Successful      1         23 Sep 19 21:55 EDT

You can also use the kubectl describe command to retrieve more detailed information about the status of the restore process.

Example:

  kubectl describe volumesnapshotrestore mysql-snap-inrestore

  Name:         mysql-snap-inrestore
  Namespace:    default
  Labels:       <none>
  Annotations:  kubectl.kubernetes.io/last-applied-configuration:
                  {"apiVersion":"stork.libopenstorage.org/v1alpha1","kind":"VolumeSnapshotRestore","metadata":{"annotations":{},"name":"mysql-snap-inrestore...
  API Version:  stork.libopenstorage.org/v1alpha1
  Kind:         VolumeSnapshotRestore
  Metadata:
    Creation Timestamp:  2019-09-23T17:24:30Z
    Generation:          5
    Resource Version:    904014
    Self Link:           /apis/stork.libopenstorage.org/v1alpha1/namespaces/default/volumesnapshotrestores/mysql-snap-inrestore
    UID:                 00474a5c-de27-11e9-986b-000c295d6364
  Spec:
    Group Snapshot:    false
    Source Name:       mysql-snapshot
    Source Namespace:  default
  Status:
    Status:  Successful
    Volumes:
      Namespace:  default
      Pvc:        mysql-data
      Reason:     Restore is successful
      Snapshot:   k8s-volume-snapshot-cb909cf9-de26-11e9-ad56-320ff611f4ca
      Status:     Successful
      Volume:     pvc-8b996a17-de26-11e9-986b-000c295d6364
  Events:
    Type    Reason      Age   From   Message
    ----    ------      ----  ----   -------
    Normal  Successful  0s    stork  Snapshot in-Place  Restore completed

Cloud backups for single PVCs