Does a DWS Snapshot Have the Same Function as an EVS Snapshot?¶
No.
GaussDB(DWS) snapshots are used to restore all the configurations and service data of a cluster. EVS snapshots are used to restore the service data of a data disk or system disk within a specific time period.
DWS Snapshot¶
A GaussDB(DWS) snapshot is a full or incremental backup of a GaussDB(DWS) cluster at a specific point in time. It records the current database data and cluster information, including the number of nodes, node specifications, and administrator name. Snapshots can be created manually or automatically.
When a snapshot is used for restoration, GaussDB(DWS) creates a new cluster based on the cluster information recorded in the snapshot and restores data from the snapshot.
For details, see "Managing Snapshots" in Data Warehouse Service Management Guide.
EVS snapshot¶
An EVS snapshot is a complete copy or image of the disk data taken at a specific time point. Snapshot is a major disaster recovery approach, and you can completely restore data of a snapshot to the time when the snapshot was created.
You can create snapshots to rapidly save the disk data at specified time points. In addition, you can use snapshots to create new disks so that the created disks will contain the snapshot data in the beginning.
You can create snapshots to rapidly save the disk data at specified time points to implement data disaster recovery.
If data loss occurs, you can use a snapshot to completely restore the data to the time point when the snapshot was created.
You can use snapshots to create new disks so that the created disks will contain the snapshot data.
For details, see section "EVS Snapshot (OBT)" in the Elastic Volume Service Product Description.