Cloud backups for single PVCs in OCP GCP
Summary and Key concepts
Summary:
This article provides a guide on creating cloud snapshots of Portworx volumes and restoring or cloning those snapshots for use in Kubernetes pods. It explains the prerequisites, including ensuring Stork is installed and configuring cloud secrets for authentication. The document covers how to create cloud snapshots using specific annotations and track their status, and it provides instructions for creating new Persistent Volume Claims (PVCs) from these snapshots using the Stork-provided stork-snapshot-sc
storage class.
Kubernetes Concepts:
- PersistentVolumeClaim (PVC): A user request for storage in Kubernetes that can be snapshotted and cloned.
- Annotations: Metadata added to Kubernetes objects for managing snapshots, including cloud snapshots.
- Namespace: Provides isolation of resources like PVCs and snapshots.
Portworx Concepts:
-
Stork: A Kubernetes extension for managing storage operations like cloud snapshots and restores.
-
VolumeSnapshot: Represents a snapshot of a Portworx volume, used for creating backups and restoring data from the cloud.
-
CloudSnap: The feature used for creating and managing cloud-based snapshots in Portworx.
This document will show you how to create cloud snapshots of Portworx volumes and how you can clone those snapshots to use them in pods.
You can restore these snapshots only in the cluster where the snapshots were taken.
Pre-requisites
Installing 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.
Configuring cloud secrets
To create cloud snapshots, one needs to setup secrets with Portworx which will get used to connect and authenticate with the configured cloud provider.
Follow instructions on the create and configure credentials section to setup secrets.
Creating cloud snapshots
The cloud snapshot method supports the following annotations:
- portworx/snapshot-type: Indicates the type of snapshot. For cloud snapshots, the value should be cloud.
- portworx/cloud-cred-id: (Optional) This specifies the credentials UUID if you have configured credentials for multiple cloud providers. In a situation where a single cloud provider is configured, this is not required.
- portworx.io/cloudsnap-incremental-count: This specifies the number of incremental cloud snapshots after which a full backup will be taken.
Example
In below example, we create a cloud snapshot for a PVC called mysql-data backed by a Portworx volume.
apiVersion: volumesnapshot.external-storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
name: mysql-snapshot
namespace: default
annotations:
portworx/snapshot-type: cloud
spec:
persistentVolumeClaimName: mysql-data
Once you apply the above object you can check the status of the snapshots using the kubectl get volumesnapshot.volumesnapshot.external-storage.k8s.io/
command with the name of your snapshot appended:
oc get volumesnapshot.volumesnapshot.external-storage.k8s.io/mysql-snapshot
NAME AGE
volumesnapshots/mysql-snapshot 2s
oc get volumesnapshotdatas
NAME AGE
volumesnapshotdatas/k8s-volume-snapshot-xxxxxxxx-xxxx-xxxx-xxxx-5a34ec89e61c 1s
The creation of the volumesnapshotdatas object indicates that the snapshot has been created. If you describe the volumesnapshotdatas object you can see the Portworx Cloud Snapshot ID and the PVC for which the snapshot was created.
oc describe volumesnapshotdatas
Name: k8s-volume-snapshot-xxxxxxxx-xxxx-xxxx-xxxx-5a34ec89e61c
Namespace:
Labels: <none>
Annotations: <none>
API Version: volumesnapshot.external-storage.k8s.io/v1
Kind: VolumeSnapshotData
Metadata:
Cluster Name:
Creation Timestamp: 2018-03-08T03:17:02Z
Deletion Grace Period Seconds: <nil>
Deletion Timestamp: <nil>
Resource Version: 29989636
Self Link: /apis/volumesnapshot.external-storage.k8s.io/v1/k8s-volume-snapshot-xxxxxxxx-xxxx-xxxx-xxxx-5a34ec89e61c
UID: xxxxxxxx-xxxx-xxxx-xxxx-0214683e8447
Spec:
Persistent Volume Ref:
Kind: PersistentVolume
Name: pvc-xxxxxxxx-xxxx-xxxx-xxxx-0214683e8447
Portworx Volume:
Snapshot Id: xxxxxxxx-xxxx-xxxx-xxxx-33c5ab8d4d8e/149813028909420894-125009403033610837-incr
Volume Snapshot Ref:
Kind: VolumeSnapshot
Name: default/mysql-snapshot-xxxxxxxx-xxxx-xxxx-xxxx-0214683e8447
Status:
Conditions:
Last Transition Time: <nil>
Message:
Reason:
Status:
Type:
Creation Timestamp: <nil>
Events: <none>
Creating PVCs from cloud snapshots
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, you would add the snapshot.alpha.kubernetes.io/snapshot
annotation to refer to the snapshot
name.
For the above snapshot, the spec would like this:
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