Merge pull request #51390 from xing-yang/volume-group-snapshot-v1beta2-blog

Add blog for volume group snapshot v1beta2

Author: k8s-ci-robot

content/en/blog/_posts/2025-08-27-volume-group-snapshot-beta-2.md

@@ -0,0 +1,73 @@
+---
+layout: blog
+title: "Kubernetes v1.34: Moving Volume Group Snapshots to v1beta2"
+draft: true
+date: 2025-XX-XX
+slug: kubernetes-v1-34-volume-group-snapshot-beta-2
+author: >
+   Xing Yang (VMware by Broadcom)
+---
+
+Volume group snapshots were [introduced](/blog/2023/05/08/kubernetes-1-27-volume-group-snapshot-alpha/)
+as an Alpha feature with the Kubernetes 1.27 release and moved to [Beta](/blog/2024/12/18/kubernetes-1-32-volume-group-snapshot-beta/) in the Kubernetes 1.32 release.
+The recent release of Kubernetes v1.34 moved that support to a second beta.
+The support for volume group snapshots relies on a set of
+[extension APIs for group snapshots](https://kubernetes-csi.github.io/docs/group-snapshot-restore-feature.html#volume-group-snapshot-apis).
+These APIs allow users to take crash consistent snapshots for a set of volumes.
+Behind the scenes, Kubernetes uses a label selector to group multiple PersistentVolumeClaims
+for snapshotting.
+A key aim is to allow you restore that set of snapshots to new volumes and
+recover your workload based on a crash consistent recovery point.
+
+This new feature is only supported for [CSI](https://kubernetes-csi.github.io/docs/) volume drivers.
+
+## What's new in Beta 2?
+
+While testing the beta version, we encountered an [issue](https://github.com/kubernetes-csi/external-snapshotter/issues/1271) where the `restoreSize` field is not set for individual VolumeSnapshotContents and VolumeSnapshots if CSI driver does not implement the ListSnapshots RPC call.
+We evaluated various options [here](https://docs.google.com/document/d/1LLBSHcnlLTaP6ZKjugtSGQHH2LGZPndyfnNqR1YvzS4/edit?tab=t.0) and decided to make this change releasing a new beta for the API.
+
+Specifically, a VolumeSnapshotInfo struct is added in v1beta2, it contains information for an individual volume snapshot that is a member of a volume group snapshot.
+VolumeSnapshotInfoList, a list of VolumeSnapshotInfo, is added to VolumeGroupSnapshotContentStatus, replacing VolumeSnapshotHandlePairList.
+VolumeSnapshotInfoList is a list of snapshot information returned by the CSI driver to identify snapshots on the storage system.
+VolumeSnapshotInfoList is populated by the csi-snapshotter sidecar based on the CSI CreateVolumeGroupSnapshotResponse returned by the CSI driver's CreateVolumeGroupSnapshot call.
+
+The existing v1beta1 API objects will be converted to the new v1beta2 API objects by a conversion webhook.
+
+## What’s next?
+
+Depending on feedback and adoption, the Kubernetes project plans to push the volume
+group snapshot implementation to general availability (GA) in a future release.
+
+## How can I learn more?
+
+- The [design spec](https://github.com/kubernetes/enhancements/tree/master/keps/sig-storage/3476-volume-group-snapshot)
+  for the volume group snapshot feature.
+- The [code repository](https://github.com/kubernetes-csi/external-snapshotter) for volume group
+  snapshot APIs and controller.
+- CSI [documentation](https://kubernetes-csi.github.io/docs/) on the group snapshot feature.
+
+## How do I get involved?
+
+This project, like all of Kubernetes, is the result of hard work by many contributors
+from diverse backgrounds working together. On behalf of SIG Storage, I would like to
+offer a huge thank you to the contributors who stepped up these last few quarters
+to help the project reach beta:
+
+* Ben Swartzlander ([bswartz](https://github.com/bswartz))
+* Hemant Kumar ([gnufied](https://github.com/gnufied))
+* Jan Šafránek ([jsafrane](https://github.com/jsafrane))
+* Madhu Rajanna ([Madhu-1](https://github.com/Madhu-1))
+* Michelle Au ([msau42](https://github.com/msau42))
+* Niels de Vos ([nixpanic](https://github.com/nixpanic))
+* Leonardo Cecchi ([leonardoce](https://github.com/leonardoce))
+* Saad Ali ([saad-ali](https://github.com/saad-ali))
+* Xing Yang ([xing-yang](https://github.com/xing-yang))
+* Yati Padia ([yati1998](https://github.com/yati1998))
+
+For those interested in getting involved with the design and development of CSI or
+any part of the Kubernetes Storage system, join the
+[Kubernetes Storage Special Interest Group](https://github.com/kubernetes/community/tree/master/sig-storage) (SIG).
+We always welcome new contributors.
+
+We also hold regular [Data Protection Working Group meetings](https://github.com/kubernetes/community/tree/master/wg-data-protection).
+New attendees are welcome to join our discussions.