Async Replication Configuration Workflows

If the Clusters are Connected through the Management Network

DataSpace provides a simplified flow for configuring async replication. This option is available specifically where the source and destination cluster(s) have interconnectivity through their management networks. For details of this procedure, see Configuring Asynchronous Replication from DataSpace.

After you configure replication from DataSpace, if you want to enable seamless failover for NFSv3 clients, create a new view on each of the clusters participating in the replication, on the path that you want to make mountable for clients. That can be the replicated path or a path contained within the replicated path. For each view that you create, enable global sync. Creating Views

If the clusters are not connected over their management networks, proceed with Configuration Workflow for Async Replication with a Single Destination to configure replication with a single destination, or Configuration Workflow for Async Replication with Multiple Destinations to configure replication with multiple destinations.

Configuration Workflow for Async Replication with a Single Destination

These steps complete the configuration of replication between two peers. To configure a replication group with more than two peers, see Configuration Workflow for Async Replication with Multiple Destinations.

Further steps are needed to prepare for smooth failover or to perform failover. See Deploying a Failed-Over Replication Peer as a Working Cluster.

Follow this workflow to configure async replication between one cluster and one other cluster:

Make sure there is a virtual IP pool on each of the peer clusters that is dedicated to replication. The role of the virtual IP pool must be set to replication.
A replication VIP pool is used exclusively for routing replication traffic between the peers and not for serving data to clients. The CNodes that are assigned virtual IPs from the replication virtual IP pool are used to communicate directly with the remote peer, while other CNodes can communicate only indirectly with the remote peer.
If there is no such virtual IP pool on any of the clusters, follow the procedure to create a virtual IP pool, and be sure to set the role to Replication.
If you want to configure replication in secure mode, with mTLS encryption, make sure that mTLS certificates are installed on every participating cluster.
Create a replication peer. This is the configuration of a replication relationship with another cluster. The peer configuration is mirrored on the destination peer.
Create a protection policy. This is a policy governing the schedule and retention parameters for replicating data to the configured peer.
Create a remote protected path. This defines a data path on the cluster to replicate, the destination path on the peer and the protection policy. You can create multiple protected paths using the same protection policy and replication peer to replicate different paths. On the remote peer, you can also set up multiple protected paths with the local peer as the destination. In other words, replication can be set up in both directions between a pair of peers.
If you want to enable seamless failover for NFSv3 clients, create a new view on the replicated path on the source peer and on the destination peer, enabling global sync on each view. Creating Views
Note
Global synchronization cannot be enabled on an existing view. It must be enabled when the view is created.

Configuration Workflow for Async Replication with Multiple Destinations

A configuration of replication between more than two replication peers involves the creation of a peer relationship and a protection policy to be configured between each and every peer in the group and each and every other peer in the group, including between destination peers. These configurations between destination peers wait on standby while data is replicated from the source to each destination. In case of a failover event requiring a change of the source, one of the destinations can become the replication source and the configuration is in place to enable replication from that new source to each destination. The configuration that enables replication between any two peers is sometimes referred to as a replication stream, such as in the VAST Web UI of previous versions.

Follow the steps below to complete a replication configuration where a source peer replicates to multiple destination peers.

Further steps are needed to prepare for smooth failover or to perform failover. See Deploying a Failed-Over Replication Peer as a Working Cluster.

Make sure there is a virtual IP pool on each of the peer clusters that is dedicated to replication. The role of the virtual IP pool must be set to replication.
A replication VIP pool is used exclusively for routing replication traffic between the peers and not for serving data to clients. The CNodes that are assigned virtual IPs from the replication virtual IP pool are used to communicate directly with the remote peer, while other CNodes can communicate only indirectly with the remote peer.
If there is no such virtual IP pool on any of the clusters, follow the procedure to create a virtual IP pool, and be sure to set the role to Replication.
If you want to configure replication in secure mode, with mTLS encryption, make sure that mTLS certificates are installed on every participating cluster.
On the primary cluster:
1. Create a replication peer for each of the other clusters in the group. Each of these replication peer configurations is mirrored on the destination cluster.
2. Create a protection policy for each replication peer. This is also mirrored on the replication peer.
3. Create a remote protected path, for replicating from the primary cluster to all the destination clusters. Initially, you can configure the remote protected path to replicate from the primary cluster to one of the destination clusters. After creating it, modify the protected path to add each of the other destination paths on the other destination clusters to the remote protected path. The protected path is mirrored on each destination peer.
  Note
  Limitations apply to protected paths for async replication. For details, see Managing Protected Paths.
  Note
  At this point, if you wish to enable seamless failover for NFSv3 clients that will access the replicated path, you can create a new view with global sync enabled on the local path and on the remote path and you can create . Otherwise, you can create these views after completing the replication group.Creating Views
On one of the other clusters in the group:
1. Create a replication peer for each of the other destination peers.
2. Create a protection policy for replicating to each of the other destination peers.
3. Edit the protected path and add each of the other destination peers to the protected path as a destination.
Repeat creation of replication peers, protection policies and destinations on destination peers as needed until all destination peers have standby replication streams to all other destination peers.
At this point, if you want to enable seamless failover for NFSv3 clients and you did not yet create views with global sync on the replication paths, create a new view on each replication peer in the replication group, on the path that you want to make mountable for clients. That can be the replicated path or a path contained within the replicated path. For each view that you create, enable global synchronization. Creating Views
Note
Global synchronization cannot be enabled on an existing view. It must be enabled when the view is created.

Adding a Member to a Replication Group

To add another peer to an existing replication group:

On the primary cluster:
1. Create a replication peer and a protection policy for the new member.
2. Edit the protected path for the group and add a destination with the protection policy that you created for replicating to the new member.
On the new member peer:
1. Create a replication VIP pool if needed.
2. Create a replication peer and protection policy for each of the other destination peers.
3. Open the group's protected path to edit it. Add each of the other destination peers as a destination, by specifying the protection policies created in the previous step.
If you want to enable seamless failover for NFSv3 clients, create a new view on the replicated path on the new peer, and enable global sync on the view. Creating Views
Note
Global synchronization cannot be enabled on an existing view. It must be enabled when the view is created.