Re: vifs not working?

[Sarton O'Brien <bsd-xen%roguewrt.org@localhost>]

On Wed, 21 May 2008 09:43:46 am der Mouse wrote:
> Okay, after a hand from two helpful listmembers, I've managed to get
> xen to start.  dom0 seems to work just fine.  But there's something
> wrong when trying to run domU machines: I can't make the network work.
> 
> The only way I've ever gotten a domU machine to start is to configure
> it with no network interfaces at all.  When trying to start one with a
> network interface, or when trying to xm network-attach an interface to
> a machine started with none, I get a long hang (three minutes?) and
> then a complaint like (this quoted from an xm network-attach; attempts
> to xm create with a nonempty vif list word it slightly differently):
> 
> Error: Device 0 (vif) could not be connected. Hotplug scripts not working.
> 
> This despite specifying "script=/usr/bin/true" on the network-attach
> command line.
> 
> What are these hotplug scripts and how can I make them start working?
> Or, alternatively, how can I suppress the error?  If I start a
> networkless machine and use network-attach on it, the xennet* and xvif*
> interfaces appear, and, as far as I can tell, they work fine - until xm
> errors out and prints a whine like the above, at which point the
> xennet* and xvif* interfaces vanish again.
> 
> The networkless domU config file I'm using is very simple:
> 
> kernel = "/boot/domU"
> memory = 128
> name = "d1"
> #vif = [ 'mac=02:00:00:00:00:01, bridge=null' ]
> vif = [ ]
> disk = [ 'file:/disks/1,1,w' ]
> root = "xbd0"
> extra = "-s"
> 
> /disks/1 is a 4G file which I set up with the help of a vnd.  (When I
> try to start the domain, the vnd is, of course, unconfigured.)
> Appended after my signature below is dmesg from the domU machine (taken
> after an attempt to use xm network-attach on it).  I got it off the
> domU machine by putting it in a file and then, after shutting down the
> domU, using vnd to get the file out of the filesystem.
> 
> Any ideas what I'm doing wrong?  I can, of course, provide more
> information if there's something important I've left out; I'm almost
> totally unfamiliar with this stuff, so please consider pilot error a
> plausible explanation - just tell the pilot what the error is!

I can't say that I've experimented much outside the standard configuration but 
it's my understanding, due to the inability to utilise pci devices within a 
domu, that a bridge interface is required for a vif to materialise.

I could be wrong but I've always ensured I have a bridge interface and have 
specified it as such in the config with no dramas to date.

Outside of having a bridge and with no pci device available (Assuming this is 
xen3), I can't imagine any other way for such a device to function.

Sarton