A 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 database administrator name. Snapshots can be created manually or automatically. For details, see Manual Snapshots and Automated Snapshots.
If you restore a snapshot to a new cluster, GaussDB(DWS) creates a new cluster based on the cluster information recorded in the snapshot, and then restores data from the snapshot. For more information, see Restoring a Snapshot to a New Cluster.
If you restore a snapshot to the original cluster, GaussDB(DWS) clears the existing data in the cluster, and then restores the database information from the snapshot to the cluster. For more information, see Restoring a Snapshot to the Original Cluster.
The snapshot backup and restoration rates are as follows. (The statistics are obtained in the lab test and are for reference only. The actual rate depends on your disk, network, and bandwidth resources.)
- Backup rate: 200 MB/s/DN
- Restoration rate: 125 MB/s/DN
- Snapshot storage space
- The cluster storage is provided by GaussDB(DWS) free of charge. Cluster storage = Storage space per node x Number of nodes
- The dependency of the snapshot service is as follows:
- Only the snapshots stored in OBS can be used to restore data to a new cluster.
- A new cluster created from the snapshot has the same configurations (including the number and flavor of nodes) as those of the original cluster.
- If you create a new cluster based on a snapshot without modifying parameters, the parameters of the new cluster will be the same as those of the snapshot.
- During snapshot creation, do not perform the VACUUM FULL operation, or the cluster may become read-only.
- Snapshot creation affects disk I/O performance. You are advised to create snapshots during off-peak hours.