Synnefo » snf-ganeti

You can run Ganeti either in "bridge mode" or in "routed mode". In bridge

mode, the default, the instances network interfaces will be attached to a

software bridge running in dom0. Xen by default creates such a bridge at

startup, but your distribution might have a different way to do things, and

you'll definitely need to manually set it up under KVM.

If you want to run in "routing mode" you need to specify that at cluster init

time (using the --nicparam option), and then no bridge will be needed. In

this mode instance traffic will be routed by dom0, instead of bridged.

In order to use "routing mode" under Xen, you'll need to change the relevant

parameters in the Xen config file. Under KVM instead, no config change is

necessary, but you still need to set up your network interfaces correctly.

By default, under KVM, the "link" parameter you specify per-nic will

represent, if non-empty, a different routing table name or number to use for

your instances. This allows insulation between different instance groups,

and different routing policies between node traffic and instance traffic.

You will need to configure your routing table basic routes and rules outside

of ganeti. The vif scripts will only add /32 routes to your instances,

through their interface, in the table you specified (under KVM, and in the

main table under Xen).

.. admonition:: Bridging under Debian

If you want to use a bridge which is not ``xen-br0``, or no bridge at all, use

the --nicparams