diff --git a/doc/install.rst b/doc/install.rst index e16650991eee1f99229eee985acec7d80655b2b7..55ea37871452a8dab8bcf859ca638134e127e588 100644 --- a/doc/install.rst +++ b/doc/install.rst @@ -326,17 +326,36 @@ Configuring the network **Mandatory** on all nodes. -Ganeti relies on Xen running in "bridge mode", which means 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. +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. Beware that the default name Ganeti uses is ``xen-br0`` (which was used in Xen 2.0) while Xen 3.0 uses ``xenbr0`` by default. The default bridge your Ganeti cluster will use for new instances can be specified at cluster initialization time. -.. admonition:: Debian +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 The recommended way to configure the Xen bridge is to edit your ``/etc/network/interfaces`` file and substitute your normal @@ -493,6 +512,9 @@ that the hostname used for this must resolve to an IP address reserved **exclusively** for this purpose, and cannot be the name of the first (master) node. +If you want to use a bridge which is not ``xen-br0``, or no bridge at all, use +the --nicparams + If the bridge name you are using is not ``xen-br0``, use the *-b <BRIDGENAME>* option to specify the bridge name. In this case, you should also use the *--master-netdev <BRIDGENAME>* option with the