Persistent and ephemeral node storage
For each node in the cluster, you can configure paths for both persistent storage and ephemeral storage.
Persistent storage is mandatory. The cluster uses persistent storage to store information that needs to persist even if a shard or a node fails, such as server logs, configurations, and files.
For example, if you configure persistence for a database, then the persistence information is stored in this location.
The persistent volume must be a storage area network (SAN) using an EXT4 or XFS file system and be connected as an external storage volume.
When using append-only file (AOF) persistence, use flash-based storage for the persistent volume.
Ephemeral storage is optional. If configured, the cluster stores temporary information that does not need to persist in the ephemeral storage. This improves performance and helps reduce the load on the persistent storage.
Ephemeral storage must be a locally attached volume on each node.
Disk size requirements
For disk size requirements, see:
- Hardware requirements for general guidelines regarding the ideal disk size for each type of storage
- Disk size requirements for extreme write scenarios for special considerations when dealing with a high rate of write commands