Backup Principles

GaussDB(for MySQL) uses Huawei's DFV storage, which decouples storage from compute. The compute layer provides services for external systems and manages logs, and the storage layer stores data. The storage layer consists of Common Log nodes and Slice Store nodes. Common Log nodes store logs, while Slice Store nodes store data.

Figure 1 Backup principles

As shown in Figure 1, the creation of backups involves in the compute layer and storage layer.

• The primary node at the compute layer reads the logs of the Common Log nodes at the storage layer and backs them up to OBS.
• The primary node at the compute layer delivers a command for backing up data to the Slice Store nodes at the storage layer. The Slice Store nodes back up data to OBS.

During the creation of a backup, the CPU usage and memory usage of the primary node of your instance increase slightly, but you will not notice anything at the storage layer. The final backup is stored in OBS as multiple data files and does not use up any of the disk space of the instance.