Does SoftNAS support VMware vMotion?
Yes, vMotion is a proactive tool for scheduled maintenance and it may take a while to migrate. The amount of time depends size of the virtual machine (VM) being moved.
Vmware HA (high availability) or FT (fault tolerance) should be used for protection against hardware or infrastructure failure. HA is restarting to another ESX server and FT creates a mirror VM in another ESX host cluster which gives you zero downtime but does have limit on number of vCPUs.
For FT, Vmware version 5.x supports only 1 vCPU. In version 6, Standard and Enterprise supports up to 2 vCPUs and Enterprise Plus support up to 4 vCPUs.