So just found out that budget Synology Units can’t run Active Backup for Business if their CPU’s aren’t enabled for virtualization
The RS819 runs a Realtek RTD1296 quad-core 1.4GHz CPU and the Package Center doesn’t offer Virtual Machine Manager or Active Backup for Business.
So you can’t use this to protect a VMWare VSphere or ESXi instance
It looks like you need an Intel or AMD CPU that supports virtualization to be able to use ABfB.
So a RS422+ will do it.