[Users] Migrate simple configuration to self-hosted

[Doron Fediuck]

----- Original Message -----
> From: "Bob Doolittle" <bob at doolittle.us.com>
> To: "users" <users at ovirt.org>
> Sent: Thursday, March 13, 2014 8:25:51 PM
> Subject: [Users] Migrate simple configuration to self-hosted
> 
> Hi,
> 
> I want to migrate my existing deployment to self-hosted. I have a simple
> deployment:
> 
> A: Machine Fedora 20
> B: libvirt VM (hosted on A) RHEL 6.5 running Engine 3.3.4-1
> C: Machine RHEL 6.5 acts as Hypervisor/Host/Node (VDSM 4.13.3-4)
> 
> ISO NFS Domain is on B
> Data (Master) NFS Domain is on C
> 
> I want to migrate VM B to Machine C, as self-hosted, and free up Machine A
> 
> When I look at these instructions:
> http://www.ovirt.org/Migrate_to_Hosted_Engine
> 
> It starts with "I installed a new host with fedora 19".
> 
> I don't understand this. Won't most people doing this migration want to
> start with their existing Hypervisor/Host/Node, and migrate their Engine
> to it? Do I really need a new 3rd machine, when my goal is to free up
> one of my 2 existing machines?
> 
> Or can I go ahead and assume these instructions are fine to apply to an
> existing Host already running VDSM 4.13.3-4?
> 
> I would have (naively?) imagined that the typical migration would be
> something like:
> 
> 0. Upgrade Engine and Host to 3.4
> 1. Create a new VM
> 2. Install OS on new VM, start it up
> 3. Backup current Engine
> 4. Stop current Engine (leave Host and VM running), change hostname
> (local and DNS), maybe power off for good luck until done
> 5. Login to new VM (probably using ssh unless there's a way to connect
> directly to the VM via Spice/VNC while the Engine is down) to:
>      A. Assign previous Engine hostname to it (local and DNS), possibly
> reboot
>      B. Set it up as a self-hosted Engine
>      C. Restore backup to it
>      D. Start up new engine
> 
> What am I missing?
> 
> Thanks,
>      Bob
> 

Hi Bob,
first of all F20 is not fully supported for the engine due to the JBoss version it uses.

As for your questions, as any admin will tell you fresh start is usually much better
than keeping old files and configurations which may or may not effect what you're
trying to install.
Since you're about to free a server to become a hypervisor, you can use one of
your other hypervisors as the first hosted engine node. The current engine machine
is not a hypervisor (missing vdsm, and probably other packages) so you'll need
to add it as a host anyway to your hosted engine setup eventually.

Having said that, you can try going your own way. This is something which may
be technically possible nut we did not try or tested it before.

Keep us updated,
Doron