Create and use local snapshots in OCP GCP
Summary and Key concepts
Summary:
This article provides a detailed guide on how to create and manage snapshots of Portworx volumes in Kubernetes using Stork. It covers the process of creating snapshots for both single PVCs and groups of PVCs using label selectors, restoring snapshots to new or existing PVCs, and performing in-place restores. The article highlights the importance of using annotations for managing snapshot operations and explains how to handle snapshots across namespaces. Additionally, it includes guidance on verifying snapshots and restoring operations using the Kubernetes CLI tools like kubectl
and Stork's CLI storkctl
.
Kubernetes Concepts:
- PersistentVolumeClaim (PVC): A request for storage in Kubernetes, used for creating and restoring snapshots.
- StorageClass: Defines how storage is provisioned, such as using the
stork-snapshot-sc
StorageClass for restoring snapshots. - Annotations: Metadata used to manage snapshots, including cross-namespace snapshot restoration.
- ClusterRole: Defines permissions for managing snapshot operations across the Kubernetes cluster.
Portworx Concepts:
-
Stork: A Portworx tool for managing storage operations, including snapshots and backups in Kubernetes.
-
VolumeSnapshot: A snapshot of a Portworx volume for backup and cloning.
-
VolumeSnapshotRestore: Used to restore a PVC from a snapshot, supporting both new PVCs and in-place restores.
Summary and Key concepts
This article provides a guide on how to create snapshots of Portworx volumes and restore them to new or existing PVCs in Kubernetes using Stork. It emphasizes the use of Stork for managing snapshots and highlights that snapshots can be created both for single PVCs and groups of PVCs using a label selector. The article outlines the process of creating snapshots, restoring them to new PVCs, and performing in-place restores. Additionally, it details how to handle snapshots across namespaces and manage snapshot operations using annotations and Kubernetes CLI tools.
Kubernetes Concepts
- PersistentVolumeClaim (PVC): A request for storage by a user in Kubernetes. PVC Docs
- StorageClass: Used to define how storage is provisioned in Kubernetes. StorageClass Docs
- Annotations: Metadata in Kubernetes used to add additional configuration, such as snapshot management. Annotations Docs
- ClusterRole: Defines permissions for Kubernetes resources at the cluster level. ClusterRole Docs
Portworx Concepts
-
Stork: An extension for Kubernetes to manage storage operations such as snapshots and backups. Stork Docs
-
VolumeSnapshot: A point-in-time copy of a Portworx volume, useful for backup or cloning. Snapshot Docs
-
VolumeSnapshotRestore: A resource used by Stork to restore a PVC from a snapshot. VolumeSnapshotRestore Docs
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 cluster. If you fetched the Portworx specs from the Portworx spec generator in Portworx 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.
Instructions on taking snapshots of single PVCs and restoring PVCs from the snapshots. Instructions on taking snapshots of a group of PVCs and restoring PVCs from the snapshots.📄 Snapshot single PVCs
📄 Snapshot group of PVCs
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.
- 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 asretain
, 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.
oc get pvc
NAMESPACE NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
default mysql-data Bound pvc-xxxxxxxx-xxxx-xxxx-xxxx-0214683e8447 2Gi RWO px-mysql-sc 2d
default mysql-snap-clone Bound pvc-xxxxxxxx-xxxx-xxxx-xxxx-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.
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 themysql-snap-restore-splocal
namespace to a PVC calledmysql-snap-inrestore
in thedefault
namespace:apiVersion: stork.libopenstorage.org/v1alpha1
kind: VolumeSnapshotRestore
metadata:
name: mysql-snap-inrestore
namespace: default
spec:
sourceName: mysql-snapshot
sourceNamespace: mysql-snap-restore-splocal - apiVersion as
-
Place the spec into a file called
mysql-cloud-snapshot-restore.yaml
and apply it:oc 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 EDTYou can also use the
oc describe
command to retrieve more detailed information about the status of the restore process.Example:
oc 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: xxxxxxxx-xxxx-xxxx-xxxx-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-xxxxxxxx-xxxx-xxxx-xxxx-320ff611f4ca
Status: Successful
Volume: pvc-xxxxxxxx-xxxx-xxxx-xxxx-000c295d6364
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Successful 0s stork Snapshot in-Place Restore completed