Creating the Secondary Instance (Target)

Please follow the instructions presented on VMware Getting Started - Deploy and Access SoftNAS Instances, remembering to add the same number of disks and configure them identically.

Note
Do NOT create a column on the second instance. The storage pool on the second instance serves as a landing strip for the volume in a failover situation.

Creating the Third Instance (Controller)

HA Controllers are relatively lightweight versions of SoftNAS, only requiring 512 MB of RAM and 1 vCPU. They also have relatively little network traffic or data change, so they pose relatively little resource overhead versus the added peace of mind, knowing that storage HA operations will remain consistent, no matter what takes place across the virtualization environment.
No special configurations are needed for the controller instance. More information can be found here.