[Users] Is it possible to run the node and engine on the same box?

[Perry Myers]

On 02/19/2012 07:17 PM, Brent Bolin wrote:
>>> and the install just not working without more then one attempt.
>>
>> Can you provide more details?  Otherwise we can't fix the issues.
> 
> Just that the installer says it fails and the only option is to
> reboot.  Sometimes going into the troubleshooting option and selecting
> "reinstall" fixes it other times not.  Makes me wonder if ovirt iso
> install can't handle pre existing partions/lvm remnants.

It should be able to.  Over the past months we've made numerous fixes
for this.

However, if you have already installed oVirt Node to the disk, you need
to select the 'Reinstall' option from the Grub menu (listed under
Troubleshooting menu option in Grub)

So perhaps what you're seeing is Install vs. Reinstall.  In any case, we
should handle this more gracefully or at least provide some add'l
diagnostics to indicate the core reason why it failed to install.

If you could file a bug against the ovirt-node component in bugzilla, we
can definitely try to make this more user friendly.

>>>  Even tried breaking in as root to install ovirt engine repos without
>>> success.  Getting some odd errors when trying to set the root password
>>> to a known value.
>>
>> Echoing what Doron said in his reply... Don't try to install oVirt
>> Engine onto oVirt Node.  The stateless nature of oVirt Node makes
>> running the mgmt server there not possible.
> 
> I don't understand this statement.  Are you talking about firewall
> stateless connections?

The filesystem in oVirt Node is stateless.  If you attempt to install an
rpm, when you reboot the changes are lost.  The entire filesystem is in
RAM aside from a few select configuration files that are manually
persisted to a 5MB config partition on disk.

>> If you want to run the Engine on the same machine as other oVirt
>> controlled VMs, then you should use a heavyweight install of Fedora and
>> put the Engine and VDSM side by side on that.
>>
>> The fact that you can't easily run oVirt Engine on the oVirt Node is not
>> a bug, or a sign of instability.  It's simply not what oVirt Node was
>> designed for.
> 
> I understand this.  However in these days of my old age I don't run
> half a dozen chassis, skins, power supplies, hd's, mb etc... like to
> use virtualization hosts for my personal lab environment.  Right now I
> accomplish this using a kvm host and virt-manager

Right.  We're not suggesting that you can't use oVirt in this way.  You
should absolutely be able to use a single physical host running Fedora
16 and on that host run both the oVirt Engine as well as vdsm, so that
you can have an 'oVirt in a single box' setup.

All we were saying here is that you can't use oVirt Node specifically to
do the above, since it's a livecd with a stateless filesystem and
contains 'just enough OS' to run virtual machines, and no where near
enough OS to run a mgmt server.

Now, what should be possible... is to run oVirt Node and run on that
node a single VM that is not managed by oVirt Engine, and run the engine
inside that VM.  However in order to do this, you'd need to get past a
chicken-egg issue with starting a VM on oVirt Node prior to it being
registered with the oVirt Engine.

I wonder if we should expose a special command/config option in oVirt
Node to allow it to run a single VM so that oVirt Engine can be
colocated as a VM.  Anyone have any thoughts on that?

> The real power from what I read about the ovirt road map is using
> native kvm, management server without the need of windows server,
> vmotion type clustering etc...

All of that is accurate

> I am going to look over Doron notes.  Specifically the networking.
> 
> Cheers... keep up the good work.

Thanks for the feedback and experimentation :)

Perry