Question 1 - if oVirt goes down... do the ovirt-nodes and VMs remain up? Can someone answer this please? :-)

Due to budget and space constraints, I currently have 2 servers total.

What if I did the following:

Server 1) Fedora 17 with KVM/Virt-manager... running oVirt as a VM (through virt-manager) off the iSCSI NAS.
Server 2) oVirt-node machine - one and only host machine for oVirt running on Server 1).

With this setup I can run VMs from iSCSI on oVirt-node Server 2).

In the event that oVirt-node Server 2) goes down... is anything stopping me from setting up my VMs on Server 1) with the iSCSI storage from the NAS and run my VMs without oVirt through virt-manager?

This would give me some form of redundancy (requiring manual intervention) in the event that my ovirt-node went down... is this a feasible setup?

To make it even more redundant, maybe I should do the following with Server 2)

Install Fedora 17 with KVM/Virt-Manager, and VDSM... in the event that Server 1) fails... I can run my VMs on Server 2) through virt-manager?

Should I just drop oVirt for now and run virt-manager on my 2 hosts, moving VMs manually (as they are running off iSCSI NAS) if a host fails? <tear>

Thank you,

Nic



On Sat, Sep 22, 2012 at 4:09 PM, Keith Robertson <kroberts@redhat.com> wrote:
On 09/22/2012 02:28 PM, Nicolas Chenier wrote:
Question - if oVirt goes down... do the ovirt-nodes and VMs remain up?


Keith, how would you set yourself up with these specs:

2 host servers (quad-core xeons with 32gigs of ram)
Are you saying that you only have 2 machines in total, or that you have 2 machines that can be dedicated hypervisors (ie. ovirt-node) and a third machine that can be a dedicated manager?

If the former then one machine must run some version of *nix compatible with oVirt Manager and, the other machine in this scenario can simply run ovirt-node.

If the latter, then you have 1 box dedicated as a manager and 2 boxes as dedicated hypervisors.  This is a fairly basic/good setup. 
1 iSCSI NAS

Starting to think there is no way to achieve HA with this setup?
Not with only 2 boxes.  No.

oVirt requires a dedicated machine?
Generally, speaking.  Yes.

Truly HA setups aren't cheap and people often have different ideas of what constitutes HA.  Offhand I would think that you would need...

- 2 boxes for the oVirt manager
- Clustering software for the manager to facilitate an active/passive setup.
- UPSs (at *least* 2) which can be controlled by clustering software.  Why?  Most clustering SW require a fence device.  These will be your fence devices.
- 2 boxes for your hypervisors (ie. ovirt-nodes).  This will facilitate fail-over from one node to the other.

HA isn't cheap and can't usually be done on 2 boxes, IMO unless you're failing over a single app.




Thank you!

Nic

PS. Could oVirt be integrated into ovirt-node on every server?



On Sat, Sep 22, 2012 at 2:16 PM, Keith Robertson <kroberts@redhat.com> wrote:
On 09/22/2012 01:09 PM, Nicolas Chenier wrote:
Hi Alan,

I have oVirt running in a VM off my Desktop (Fedora 17 w/ KVM & Virt-Manager) off my iSCSI NAS.

I've attached Server #1 as my first host (it's running ovirt-node).

In the process of setting up my storage domains. I have a few questions to the experts out there:

1) How do I add my CD .ISOs to setup new VMs? Create iSCSI storage domain? But then how do I copy my ISOs to it?
Create an ISO storage domain and use the ovirt-iso-uploader to add your ISOs and .vfd files into that domain.


2) Can I run my oVirt VM from ovirt-node machine, without running it in oVirt (ie. setup iSCSI in virt-manager (as it is now) and run oVirt from virt-manager... then I can manage my hosts through that ovirt VM?
Huh?  You could run the oVirt Manager from a VM managed by virt-manager... yes.  Running the oVirt manager inside a VM on a hypervisor (ie. ovirt-node) controlled by that same manager isn't supported AFAIK because the mgr. could get fenced. 

To summarize, you can pretty much run the oVirt manager on any supported OS as long as that OS instance isn't running on a hypervisor (ie. ovirt-node) controlled by *that* manager.

If you haven't noticed the vocabulary to describe the various components can get a little confusing. ;) 



Not sure if I'm making myself clear... but I'm making progress. I think as long as you are not managing your oVirt vm through oVirt itself, the solution should work fine! Just trying to see if I can get that done on an ovirt-node machine...

Thank you,

Nic


On Fri, Sep 21, 2012 at 3:31 PM, Alan Johnson <alan@datdec.com> wrote:
On Wed, Sep 12, 2012 at 9:22 PM, Nicolas Chenier <dascope@gmail.com> wrote:
I was under the impression that my oVirt VM would show up in oVirt and that I could manage it through there...
 
What you're saying is that I should just run it seperatly and not manage it with itself (oVirt)? keep it on my shared storage so that I can run it off any of the 2 servers? But not manage it with oVirt (itself). I think I'm starting to get it now...
 
I really appreciate your help!
 
Nic

Nic, how did you make out with this?  I'm looking to do the same thing and am wondering if there is any risk in running the engine on a VM managed by the same engine, as you were suggesting before.  Did you give this a shot?

Itamar, why did you steer Nic away from this?

_______________
Alan Johnson
alan@datdec.com
 



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