After using oVirt for about three months I have some questions that really haven't been answered in any of the documentation, posts, or found in searching.  Or maybe more correctly I've found some answers but am trying to put the pieces I've found together.

My setup is one physical host that used to run VMware ESXi6 and it handled running the VMs on an iSCSI LUN on a Synology 3615xs unit.  I have one physical Windows workstation and all the servers, DNS, DHCP, file, etc. are VMs.  The VMs are on an iSCSI LUN on the Synology.

* Hosted-engine deployment - Run Engine as a VM.  This has the advantage of using one machine for host and running the Engine as a VM but what are the cons of it?

* Can I run the Engine on the host that will run the VMs without running it on a VM?  That is I install the OS on my physical box, install Engine, then setup datastores (iSCSI LUN), networking etc.

* How do I run more than one Engine.  With just one there is no redundancy so can I run another Engine that access the same Datacenter, etc. as the first?  Or does each Engine have to have it's own Datacenter and the backup is achieved by migrating between the Engine's Datacenters as needed.

* Given I have a hosted Engine setup how can I "undo" it and  get to running just the Engine on the host.  Do I have to undo everything or can I just install another instance of the Engine on the host but not in a VM, move the VMs to it and then remove the Engine VM.

* System shutdown - If I shutdown the host what is the proper procedure?  Go to global maintenance mode and then shutdown the host or do I have to do some other steps to make sure VMs don't get corrupted.  On ESXi we'd put a host into maintenance mode after shutting down or moving the VMs so I assume it's the same here. Shutdown VMS since there is nowhere to move the VMS, go into global maintenance mode. Shutdown.  On startup the  Engine will come up, then I start my VMs.

* Upgrading engine and host - Do I have to go to maintenance mode then run yum to install the new versions on the host and engine and then run engine-setup or do I need to go into maintenance mode?  I assume the 4.0 production install will be much more involved but hopefully keeping updated will make it a little less painful.