Secondary site is down shows the traffic flow if the secondary site goes down and FusionSync is paused but not suspended.

A write from Edges is not acknowledged by the primary Core. The Edges start to buffer the writes locally. Read operations from the Core and read and write operations in the branch office between the Edge and hosts are being performed as usual.

Replication is suspended at the secondary site shows the traffic flow if FusionSync is suspended at the secondary site.

1. A write operation is asynchronously propagated to the primary Core (Core X) from the Edge.

2. The Core applies the write operation to backend storage and logs the write to Journal LUN.

3. The backend storage acknowledges the write.

4. Wait for the write to be journaled.

5. The Core acknowledges the write to the Edge.

Primary site is down shows the traffic flow if the primary site (Data Center A) is down and the failover is initiated. The secondary Core assumes the primary role and the connected Edges failover to the secondary site (Data Center B).