Dell Storage Manager 2020 R1 Administrator's Guide

How Replication Works

Replication leverages snapshots. The first time you replicate a NAS volume, the FluidFS cluster copies the entire contents of the NAS volume. For subsequent replication operations, the FluidFS cluster copies only the data that changed since the previous replication operation started. This design allows for faster replication, efficient use of system resources, and saves storage space while keeping data consistent. Replication is asynchronous, meaning that each source NAS volume can have a unique schedule for replicating data to the target NAS volume.

The amount of time replication takes depends on the amount of data in the NAS volume and the amount of data that has changed since the previous replication operation.

When replicating a NAS volume to another FluidFS cluster, the other FluidFS cluster must be set up as a replication partner. Each FluidFS cluster can have multiple replication partners, enabling you to replicate different NAS volumes to different partners, depending on operational requirements. However, each individual NAS volume can be replicated to only one target NAS volume on one replication partner. The following figure summarizes which replication scenarios are supported.

After a partner relationship is established, replication between the partners can be bidirectional. One system could hold target NAS volumes for the other system as well as source NAS volumes to replicate to that other system.

A replication policy can be set up to run according to a set schedule or on demand. Replication management flows through a secure SSH tunnel from system to system over the client network.

To access or recover data, you can promote a target NAS volume to a recovery NAS volume and grant clients access to the recovery NAS volume data. The recovery NAS volume will appear as if it is a local NAS volume.