PVC Backup Modes

To ensure the backup of PVC data, there are three available modes:

Standard Mode: In this mode, the tar program generates a tar pipe from the original data in the PVC, and then the plugin backs it up. a drawback of this method is that if a file is being written while the tar pipe is generating, it may cause issues with the backup and compromise data integrity. On the positive side, this backup mode is slightly faster than the others.
Clone Mode: The plugin instructs the Kubernetes cluster to clone a persistent volume, followed by backing up all data from this PVC. However, this backup method lacks data consistency guarantee. The persistent volume CSI driver needs to support Volume Cloning in order to utilize this backup mode.
Snapshot Mode: The plugin initiates a request to the Kubernetes Cluster for a snapshot of the persistent volume, followed by a request to create a PVC from the snapshot volume. Subsequently, the plugin proceeds to back up all data, ensuring data consistency. To utilize this backup mode, the persistent volume CSI driver must be compatible with Volume Snapshot.

In terms of data consistency, the order is as follows: snapshot, clone and standard. Nevertheless, not all persistent volumes are capable of supporting snapshot technology. It is crucial to verify the compatibility of this technology. In case Snapshot is not supported, the plugin will seamlessly transition to Clone, and if Volume Cloning is not supported, it will then move to Standard.