---
title: "Recovery Scenarios for Combined Sync and Async Replication"
slug: "recovery-scenarios-for-combined-sync-and-async-replication"
tags: ["5.4"]
updated: 2026-10-28T01:53:46Z
published: 2026-10-28T01:53:46Z
canonical: "docs.vastdata.com/recovery-scenarios-for-combined-sync-and-async-replication"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vastdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Recovery Scenarios for Combined Sync and Async Replication

> [!NOTE]
> Note
> 
> There may be preparatory steps that you would like to take before performing failover or while your cluster is operating normally in order to be prepared to switch client applications over to the replication peer. See [Deploying a Failed-Over Replication Peer as a Working Cluster](/docs-5-4/docs/deploying-a-failed-over-replication-peer-as-a-working-cluster).

The following recover scenarios are supported for a protected path (on' Cluster A') that has a sync replication destination (on 'Cluster B') and an async replication destination (on 'Cluster C'), per the configuration described in [Combining Synchronous and Asynchronous Replication](/docs-5-4/docs/configuring-a-synchronous-and-asynchronous-replication-group-en):

1. [Turnover](/docs-5-4/docs/recovery-scenarios-for-combined-sync-and-async-replication#graceful-turnover-to-the-secondary-sync-replication-peer-vast-web-ui) from 'Cluster A' to 'Cluster B', so that 'Cluster B' can become the primary cluster.
2. [Ungraceful failover](/docs-5-4/docs/recovery-scenarios-for-combined-sync-and-async-replication#ungraceful-failover-to-the-async-replication-destination-peer) to 'Cluster C' in the event that 'Cluster A' and 'Cluster B' both become unreachable.
3. After 'Cluster A' and/or 'Cluster B' become reachable, to restore data written to 'Cluster C' while they were down, establish [async replication with 'Cluster C' as the source](/docs-5-4/docs/recovery-scenarios-for-combined-sync-and-async-replication#replicate-from-cluster-c-after-failover).
4. Subsequently, [failback to 'Cluster A'](/docs-5-4/docs/recovery-scenarios-for-combined-sync-and-async-replication#fail-back-to-cluster-a-after-ungraceful-failover).

## Graceful Turnover to the Secondary Sync Replication Peer (VAST Web UI)

1. On the secondary sync peer, open the **Protected Paths** tab of the **Data Protection** page.
2. Right-click the protected path, select **Replications** and then **Modify Replication State**.
3. The **Modify replication state** dialog shows that the expected state change after fail over.
4. Click **Turn Over**.

The secondary sync rep cluster becomes the source and starts to replicate to the async destination.

## Ungraceful Failover to the Async Replication Destination Peer

1. On the async destination peer, cluster C, open the **Protected Paths** tab of the **Data Protection** page.
2. Right-click the protected path, select **Replications** and then **Modify Replication State**.
3. The **Modify replication state** dialog shows that the expected state change after fail over.
4. Click **Fail Over**.

While the failover is in progress, the protected path *role* on 'Cluster C' appears as *Becoming Standalone*. When failover is complete, the role on Cluster C becomes *Stand alone*. Cluster C is now writeable and is not replicating to any of the other peers.

## Replicate from Cluster C after Failover

1. Once again, on the now standalone 'cluster C', right-click the protected path, select **Replications** and then **Modify Replication State**.
2. In the **Modify replication state** dialog, click **Become Source**.

When the process is complete, the role of the protected path on 'Cluster C' shows as *Source*, and Cluster C begins replicating to the available destination(s).

## Fail Back to Cluster A after Ungraceful Failover

1. On the async destination peer, cluster C, open the **Protected Paths** tab of the **Data Protection** page.
2. Right-click the protected path, select **Replications** and then **Modify Replication State**.
3. The **Modify replication state** dialog shows that the expected state change after fail over.
4. Click **Fail Over**.

While the failover is in progress, the protected path *role* on 'Cluster C' appears as *Becoming Source*. When failover is complete, the role on Cluster C becomes *Source*. Cluster C is now the writeable source of async replication. Any other peers in the replication group that are reachable become destinations.