Tutorial: How to Migrate an Access Server Cluster⁠

1. Take a backup of the following MySQL tables:

   as_certs
   as_config
   as_notification
   as_userprop

2. Use mysqldump (or your preferred MySQL backup method) to export these tables.

Use the new Access Server installation to initiate a fresh cluster and connect it to the new MySQL database.

If your migration includes upgrading Access Server to a newer version, perform the upgrade before adding additional nodes.

Refer to this tutorial: Tutorial: Update Your Access Server Version.

Once the upgrade is complete and the primary node is running the desired version, you can add new nodes.

Add additional nodes to complete the migration.

1. Sign in to the Admin Web UI on each new node.

2. Click VPN Server.

   • The Network Settings tab displays.

3. Click the Clustering & Failover tab.

4. Click Join Cluster.

5. Enter the required information to join the existing cluster.

6. Click Save and Restart.

If you access your cluster through a DNS round-robin hostname, update the DNS records so clients resolve to the new cluster nodes instead of the old ones.

1. Identify the DNS A records used for VPN client connections (for example, vpn.example.com).

2. Remove the IP addresses of the old cluster nodes from the DNS record set.

3. Add the new IP addresses of the new cluster nodes.

4. Lower the DNS TTL temporarily (for example, to 60-300 seconds) to speed propagation during the transition.

5. Verify resolution from multiple locations using:

   nslookup vpn.example.com

   • An example output:

     Server:         203.0.113.254
     Address:        203.0.113.254#53
     
     Non-authoritative answer:
     Name:   vpn.example.com
     Address: 198.51.100.10
     Name:   vpn.example.com
     Address: 192.0.2.159

6. Confirm that VPN clients can resolve and connect to the new cluster nodes successfully.

After your new cluster is fully operational, upgraded (if applicable), and all desired nodes have joined:

1. Shut down Access Server services on each old cluster node:

   service openvpnas stop

2. Remove or archive old server instances according to your organization's process.

3. Update firewall rules, monitoring systems, or infrastructure automation to remove references to the old nodes.

4. Verify that no client traffic reaches the old cluster and that the new environment now handles all sessions.