content/operate/rs/7.8/installing-upgrading/install/plan-deployment/persistent-ephemeral-storage.md
For each node in the cluster, you can configure paths for both persistent
storage and ephemeral storage. To do so, the volume must have full permissions for user and group redislabs or users:group redislabs:redislabs. See the [Customize system user and group]({{< relref "/operate/rs/7.8/installing-upgrading/install/customize-user-and-group" >}}) page for instructions.
{{< note >}} The persistent storage and ephemeral storage discussed in this document are not related to Redis persistence or AWS ephemeral drives. {{< /note >}}
Persistent storage is mandatory. The cluster uses persistent storage to store information that needs to persist if a shard or a node fails, such as server logs, configurations, and files.
To set the frequency of syncs, you can configure [persistence]({{< relref "/operate/rs/7.8/databases/configure/database-persistence" >}}) options for a database.
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, temporary information that does not need to be persisted is stored by the cluster 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.
For disk size requirements, see: