On Mon, Jun 25, 2012 at 5:32 PM, Mike Lovell <m...@dev-zero.net> wrote: > On 06/25/2012 09:33 AM, Mike Lovell wrote: >> >> On 06/25/2012 04:40 AM, Stefan Hajnoczi wrote: >>> >>> Have you looked at QEMU's net/vde.c backend? >>> >>> Does VDE (http://vde.sourceforge.net/) already do everything that QDES >>> does? >>> >>> Stefan >> >> >> I have looked at VDE and used it for a few things. I think QDES has an >> advantage over VDE in that it doesn't require additional steps to get up and >> running. With VDE, one has to at least start a vde_switch process on the >> host for the guest to connect to. Then, if multiple hosts are being used, >> the multiple vde_switch processes have to be connected. Maybe through some >> vde_plug processes connected through netcat or ssh. Its a few extra steps >> that can be a pain in a dynamic environment. With QDES, the only >> configuration should be the options to QEMU as long as the multiple hosts >> can send and receive data through the same multicast address. >> >> QDES doesn't have anywhere close to the feature set that VDE does. This >> doesn't do VLANs at the switching level. It doesn't support STP so >> connecting it to other bridges might cause weird behavior. Etc. But it does >> provide a really easy way for multiple guests on multiple hosts to be >> connected. > > > Oh. I forgot another reason why I decided to do this over using VDE. I'll do > this one with an example. Say you have 3 virtual machines on 3 different > hosts. Each host has a vde_switch process running, Switch A, B, and C. Each > vde_switch has connections to the other 2 through some vde_plug's and > netcat. In this case, VDE will disable one of the links between switches to > prevent loops, say the link between Switch A and C. Traffic from the VM > connected to Switch C that is destined for the VM on Switch A will have to > traverse through Switch B. This is a suboptimal traffic flow. Especially > when you consider that the traffic has to flow through 3 to 4 additional > processes on each host for each direction.
I haven't tried VDE myself but this sounds odd. Why can't you run a single vde_switch instance and connect multiple guests to it (with netcat)? Stefan
