[Ovirt-devel] only seeing one NIC in network device editor

[David Lutterkort]

On Fri, 2009-06-12 at 11:59 -0400, Scott Seago wrote:
> > Maybe Hugh or someone else has other thoughts on how to handle guest 
> > pxe/provisioning -- it's something we're still discussing.

What we need for PXE provisioning are two things: (1) a DHCP server and
(2) a TFTP server.

For a fairly simple virt management setup, we can continue to assume
that the admin for the ovirt infrastructure sets up and manages DHCP in
a 'reasonable' manner.

For a cloudier setup, we need to manage MAC addresses[1], IP assignments
etc. a lot more tightly anyway, so we'd need to run a DHCP server for
that anyway. There's a bit of a topology headache there, since DHCP is
based on broadcasts, and we need to be sure that the broadcasts don't
get stuck at some switch before they reach our DHCP server - we might
want to run something like dhcprelay on each node to route all DHCP
requests through the admin network.

Providing TFTP is much simpler, since it's IP based - we only need to
make sure that the address of the TFTP server that our DHCP server hands
out can be routed from the guest. By its nature, we'd want the TFTP
server to be very close to the cobbler server (I don't see a reason why
it wouldn't be on the same box) I am not sure though whether we'd want
the actual TFTP traffic on the admin network, or if we'd want that on
the guest network.

Cobbler (or any other service that you might want to offer to guests and
allow them to administer them somewhat) is a good example where you get
into 'Infrastructure as a Service' territory; besides the plumbing
concerns above, in a cloud setup, we'd want to give each user the
illusion that they have their own cobbler server, probably seeded with
some default images, but then let them manage that server, upload
kickstarts etc. to their heart's content.

David

[1] For cloud, we also need assign a range of MAC addresses and IP
addresses to each VM pool