Before setting up SNAP HA™, set up SnapReplicate™ according to the guidance in Setting up SnapReplicate. If configuring Dual Controller HA™, remember that it applies only to shared object storage, and is automatically configured via the below methodology after selecting Shared Pool prior to creating your storage pool.

For more detailed setup instructions, check SnapReplicate.

Setting Up SNAP HA™

  • From the SoftNAS SnapReplicate panel, click on Add SNAP HA™.
  • Click Next on the Welcome screen.

  • If deploying HA for an Azure pairing, or from an Azure virtual machine to AWS or VMware, Azure credentials will be required. These will auto-populate based on configuration choices made during virtual machine setup. Click next to continue.

  • Add the Virtual IPs of both the primary and secondary instances when prompted by the SnapReplicate interface. When creating your Virtual IP, be sure that the IP chosen lies outside the chosen CIDR block selected for the two replication nodes.

  • Provide the administrator credentials if prompted. However, in most cases, your IAM policy will handle this. 
  • In the case that you have previously provided Access Key and Secret Key credentials on AWS, but have later assigned an IAM role for the instance, please see Changing from Access Key/Secret Key to IAM Role on AWS.

  1. Next, we can fine tune our HA deployment. 
    1. You can determine the max number of retries before your virtual machine fails over.
    2. You can determine the max time (in seconds) that storage can be unavailable before a failover is triggered.
    3. You can also set a default for max ioping request time, to ensure that a failover is triggered more quickly in event of failure.
    4. Finally, you can determine the behavior of the failed node during a failover. 
      1. Reboot - this is the default option, allowing for quicker recovery and re-establishment of high availability, as the failed node will reboot, and SNAP HA will be reactivated, with the original node set as secondary.
      2. Shutdown - The failed node will remain shut down. You will need to reboot the instance manually to re-establish high availability. 
      3. None (No action taken) - This option is only for debug or support use. The failed node will remain in its current state. 
  2. Click Next to continue.

  • Click on Finish.

At this point SoftNAS® will do all of the heavy lifting that is required to establish HA, without the need for any user intervention. The process may take several minutes. After completion, the High Availability SoftNAS® pair has been successfully set up across Availability Zones.

SoftNAS strongly recommends to further safeguard against data loss without compromising performance by creating a write log, or ZIL.  For instructions on how to configure a ZIL/write log, see Configuring Read Cache and Write Log.