How to perform a failback to a designated cloud

How to perform a failback to a designated cloud


Perform a failback procedure to a designated cloud platform using a "reverse migration" method.


If you have been using VMware, Flexible Engine or OpenStack as your source environment, please refer to our applicable Documentation. This article provides joint instructions for failback migration to all other supported cloud platforms (AWS, Azure, Alibaba Cloud). 

Once the problem causing malfunction of the main cloud platform has been resolved and the DR solution is no longer required, it's time to run a failback of your instances, your workloads including all changes accumulated on the backup platform since the launch of the cloud site and redirect the user traffic accordingly.

The following instructions present the principles of a standard live migration, which may be familiar, but these steps involve certain adjustments for the "reverse" flow of the process to run correctly:
  1.  First off, please request our Support team ( to provide a migration kit that would include an appropriate Acura image for your cloud.
  2. This image is then used to deploy a new Hystax Acura instance on the eventual failback platform. The host performance requirements apply: 4 vCPU, 16 Gb RAM and 100Gb disk. Associate a public IP with the created machine. 
Security groups must allow the following traffic:
Hystax Acura host:                          Hystax Cloud Agent (spawned automatically in the Target Project):
•  Ingress – tcp/443;                          ○  Ingress – tcp/80;
•  Ingress – tcp/4443;                        ○  Ingress – tcp/3260;
•  Ingress – udp/12201;                      ○  Ingress - tcp/15000.

      3. To start using Acura, you need to perform its routine configuration for the desired cloud by accessing the Hystax Setup wizard via a web browser: https://<ip_address of the machine>/
      4. Uninstall the old replication agents from the machines. Make sure the following folders are deleted as well:

For Windows Replication Agent:
If you can't see this folder, check that hidden files and folders are displayed.
After that, you can install the agent. 

For Linux Replication Agent:
sudo rm -rf /etc/hystax
After that, you can install the agent.

      5.  Access the new Acura instance from the failover machines to download replication agents depending on their OS. (Internal replication agents are installed directly on failover machines)
      6. Once the agents have been installed, the relevant machines will appear in the Acura Control Panel on the customer dashboard in the Discovered state. You will now be able to start the replication process by clicking the corresponding button next to the individual machine or using "Bulk actions" section for the whole group. The machines will be replicated to the target cloud. Initially, Hystax Acura takes a full replica and, after that, incremental replicas according to a schedule set globally for a group or for any machine individually.

All replications take place in the background and do not require failover downtime till the final cutover. You can run an unlimited number of test failbacks/migrations.

      7. As this is a "reverse migration", a predefined Migration plan is needed to specify the machines that are to be migrated, their ranks, IP addresses, networks and boot delays. The Migration Plans section of the ACP lets you create one using either Basic or Expert modes (you can refer to a similar DR JSON script).
      8. When migration is initiated, the new VMs are launched in Cloud Sites from the corresponding restore points and can be checked for health.
      9. Once you feel satisfied with the result of a test migration (as you can always delete it and start a new one), you can click on the "Detach" button to perform the final cutover. Hystax Acura will be detached from the current migration and will stop tracking any related resources. The failback is complete!

If you need more detailed instructions for the Migration process, please refer to our Step-by-step Guide. Contact our Support team at for further assistance.