4:30 p.m.
На 21 юни 2020 г. 23:26:32 GMT+03:00, David White via Users <users(a)ovirt.org>
написа:
I'm reading through all of the documentation at
https://ovirt.org/documentation/, and am a bit overwhelmed with all of
the different options for installing oVirt.
My particular use case is that I'm looking for a way to manage VMs on
multiple physical servers from 1 interface, and be able to deploy new
VMs (or delete VMs) as necessary. Ideally, it would be great if I could
move a VM from 1 host to a different host as well, particularly in the
event that 1 host becomes degraded (bad HDD, bad processor, etc...)
I'm trying to figure out what the difference is between an oVirt Node
and the oVirt Engine, and how the engine differs from the Manager.
I get the feeling that `Engine` = `Manager`. Same thing. I further
think I understand the Engine to be essentially synonymous with a
vCenter VM for ESXi hosts. Is this correct?
Generally speaking they are
interchangeable, but usually the engine is the deamon that is running inside the manager.
Correct, just like in VMware - you can have your Vcenter in a VM on the esxi or you
can host it on a separate physical server.
If so, then what's the difference between the `self-hosted` vs
the
`stand-alone` engines?
Self hosted -> the manager is managing the host that is
hosting it , while standalone is on a non-managed location - like standalone KVM VM,
VMware VM or physical server.
oVirt Engine requirements look to be a minimum of 4GB RAM and 2CPUs.
oVirt Nodes, on the other hand, require only 2GB RAM.
Is this a requirement just for the physical host, or is that how much
RAM that each oVirt node process requires? In other words, if I have a
physical host with 12GB of physical RAM, will I only be able to
allocate 10GB of that to guest VMs? How much of that should I dedicated
to the oVirt node processes?
oVirt Node -> a kind of ready to go appliance that has only 1 purpose - Hosting
VMs. It has an advantage that you can easily rollback updates. Drawback - hard to
customize (for example custom drivers).
It will be nice to have as much memory as possible, but depends on the ammount and
type of VMs you plan to host on it.
Can you install the oVirt Engine as a VM onto an existing oVirt Node?
And then connect that same node to the Engine, once the Engine is
installed?
That's what the Hosted-Engine deployment is doing for you. The
easiest way is to use the cockpit method.
Reading through the documentation, it also sounds like oVirt Engine
and
oVirt Node require different versions of RHEL or CentOS.
I read that the Engine for oVirt 4.4.0 requires RHEL (or CentOS) 8.2,
whereas each Node requires 7.x (although I'll plan to just use the
oVirt Node ISO).
oVirt 4.3 (node, engine) are based on CentOS/EL 7.X
oVirt 4.4 (node, engine) are based on CentOS/EL 8.
oVirt 4.4 still needs some polishing, but keep in mind that migration from 4.3 to 4.4
requires redeploy (real reinstall).
I'm also wondering about storage.
I don't really like the idea of using local storage, but a single NFS
server would also be a single point of failure, and Gluster would be
too expensive to deploy, so at this point, I'm leaning towards using
local storage.
It's up to you.
>Any advice or clarity would be greatly appreciated.
>
>Thanks,
>David
>
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