Proposing a new infra design

[Ewoud Kohl van Wijngaarden]

On Sun, Jun 09, 2013 at 08:03:32AM -0400, Kiril Nesenko wrote:
> Ewoud Kohl van Wijngaarden wrote:
> > On Sun, Jun 09, 2013 at 02:40:02AM -0400, Kiril Nesenko wrote:
> > > This is the design that I propose:
> > >
> > > amazon vm1(engine) USA -
> > >                    |
> > >                    |- rackspace01.ovirt.org
> > >                    |- rackspace02.ovirt.org
> > >
> > > amazon vm2(engine) France -
> > >                    |
> > >                    |- alterway01.ovirt.org
> > >                    |- alterway02.ovirt.org
> >
> > Regarding the amazon engines: don't you need some layer 2 networking
> > between the manager and the hosts? Wouldn't a VM at rackspace be much
> > better as an engine because of lower latency? Maybe rackspace can just
> > provide a VLAN between the engine and hosts which should make our
> > management much easier? Maybe we can try to achieve a similar situation
> > at Alterway?
>
> If would be great !

I'd propose that we try to set up rackspace using this design and when
we know this is running well, we look at converting/upgrading alterway.

>
> >
> > > - Storage
> > > * For this design we need storage services that will be located in the
> > >   same DCs as our bare metal hosts.
> >
> > Could we use gluster where possible? At alterway for example. For
> > rackspace I'd prefer local storage per node, but I'll get to that later.
>
> gluster is a possible solution, but for gluster we still need external storage.

You can run gluster on the hosts. Then you don't need external storage.

> Why do you want to use a local storage :) ?

For rackspace nodes, I'd prefer to use local storage for jenkins slaves.
Once we set them up properly I think they can be considered throw away
thus don't need HA. By using direct attached storage you can gain some
extra performance. If we have hosts that do need HA (if we were to run
the jenkins master there for example), I'd prefer using some form of
shared storage so we can do failovers.

>
> >
> > > * Storage for resources.ovirt.org - make no sense that VM stores RPMs
> > >   on it. Much better to use a VM with a small HD and use external
> > >   storage for storing RPMs.
> >
> > I don't quite understand this. I get that you'd want different
> > partitions, but why external storage? Whether the host manages this or
> > the guest, does it really make a difference?
>
> I am not sure on which servers resources.ovirt.org is running right
> now, but I would like to run our infra on our servers. For this
> purpose its better to create a VMs with a small HD and use ext.
> storage to save RPMs on it.

Currently it's running on linode01. I still don't see the difference
between the hypervisor using the shared storage (nfs/iscsi/gluster/...)
and the VM. One advantage of the hypervisor doing it, is that you don't
have to worry about access to storage on the VM.