connecting dom0 directly to the bridge (was: performance problems...)

connecting dom0 directly to the bridge (was: performance problems...)

[Goetz Bock]

On Thu, Jan 12 '06 at 12:24, Ian Pratt wrote:
> You haven't connected dom0 directly to the bridge rather than vif0.0
> to the bridge have you?
I've been doing that with xen 2.0 and xen 3.0.0, what's bad about doing
this?
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RE: connecting dom0 directly to the bridge (was:performance problems...)

[Ian Pratt]

 
> On Thu, Jan 12 '06 at 12:24, Ian Pratt wrote:
> > You haven't connected dom0 directly to the bridge rather 
> than vif0.0 
> > to the bridge have you?
> I've been doing that with xen 2.0 and xen 3.0.0, what's bad 
> about doing this?

You shouldn't connect directly if you run services in dom0 for the
domU's. Using vif0.0 prevents a possible deadlock.

Ian

RE: connecting dom0 directly to the bridge(was:performance problems...)

[James Harper]

> > On Thu, Jan 12 '06 at 12:24, Ian Pratt wrote:
> > > You haven't connected dom0 directly to the bridge rather
> > than vif0.0
> > > to the bridge have you?
> > I've been doing that with xen 2.0 and xen 3.0.0, what's bad
> > about doing this?
> 
> You shouldn't connect directly if you run services in dom0 for the
> domU's. Using vif0.0 prevents a possible deadlock.
> 

I must be missing something here... doesn't the init script itself add
eth0 to xen-br0??? Does dom0 somehow internally create vif0.0 as a
mirror of eth0?

You said 'You haven't connected dom0 directly to the bridge rather than
vif0.0 to the bridge have you?'... I took that to mean 'You haven't
connected eth0 in dom0 directly to the bridge rather than vif0.0 to the
bridge have you?'... was that the right interpretation?

My DomU is a mail server, so it needs to connect to the external
network, not just Dom0.

Thanks

James

Re: connecting dom0 directly to the bridge(was:performance problems...)

[Goetz Bock]

On Fri, Jan 13 '06 at 08:00, James Harper wrote:
> > > On Thu, Jan 12 '06 at 12:24, Ian Pratt wrote:
> > > > You haven't connected dom0 directly to the bridge rather than
> > > > vif0.0 to the bridge have you?
> > >
> > > I've been doing that with xen 2.0 and xen 3.0.0, what's bad
> > > about doing this?
> > 
> > You shouldn't connect directly if you run services in dom0 for the
> > domU's. Using vif0.0 prevents a possible deadlock.
> > 
> 
> I must be missing something here... doesn't the init script itself add
> eth0 to xen-br0??? Does dom0 somehow internally create vif0.0 as a
> mirror of eth0?
What the init script does is:
- rename eth0 to peth0
- make a bridge xen-br0
- add peth0 to the bridge
- create a virtual interface (vif0.0?) add it to the bridge
- (some how create a new interface named eth0 and connect it (via
  vif0.0?) to the bridge too)
- configore the old IP to this new interface

What I've been doing on all my xen and uml boxes, ever since:
- make a bridge: xen-br0
- add eth0 to the bridge
- configure the systems (dom0) IP to xen-br0

Seamed to work fine. But now that I think of it, I might have some
deadlocks, but they always locked up eth0 in a way that I had to
unload/reload the module...

BTW: when replying to my mails, could you PLEASE not also CC me. I read
     this list. If time permits all posts.
--  
/"\ Goetz Bock at blacknet dot de  --  secure mobile Linux everNETting
\ /       (c) 2006 Creative Commons, Attribution-ShareAlike 2.0 de
 X   [ 1. Use descriptive subjects - 2. Edit a reply for brevity -  ]
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