WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

Re: [Xen-users] Networking with more NIC's

On Sat, Mar 17, 2007 at 11:22:24PM +0100, Peter Fastré wrote:
> 
> root@vm01:~# brctl show
> bridge name     bridge id               STP enabled     interfaces
> xenbr0          8000.feffffffffff       no              vif0.1
>                                                        peth0
> 
> Seems to be a little better? But the default route is still gone after
> starting xen.
> 

I'm pleased with this part. But the rest is bugging me now.

> 
> Reboot your server to give it a fresh start. Then check 'ifconfig' and
> >also 'brctl show' to see that there is only the one bridge, xenbr0. If
> >all looks well, then try to start a DomU.
> 
> 
> Still no success.
> I'm doing some research on my own (mailling list/internet/configuration
> examples), and tried a lot of different values in the .sxp files, in the
> configuration files.
> I tried changing the vif section:
> 
> # By default, no network interfaces are configured.  You may have one
> created
> # with sensible defaults using an empty vif clause:
> #
> # vif = [ '' ]
> #
> # or optionally override backend, bridge, ip, mac, script, type, or vifname:
> #
> # vif = [ 'mac=00:16:3e:00:00:11, bridge=xenbr0' ]
> #
> # or more than one interface may be configured:
> #
> # vif = [ '', 'bridge=xenbr1' ]
> 
> When I read this, one would think that it's possible to boot a vm without
> network interface? I know this wouldn't make sense, but it could be useful
> for testing, not? But when I remove the vif option, the vm also doesn't
> boot.
> 

I just checked back over previous posts, and I can't find whether or not
I asked you to make certain that:

    (vif-script vif-bridge)

is set in your xend-config.sxp. This is the default setting, but I think
you should check just in case.

If you wanted to try to test with *no* DomU interfaces, you should set
vif as follows:

    vif = []

This is actually a python script and you want to define an empty list -
not no list. 

If you wanted to tell vif-bridge explicity to use the bridge we created
you would do:

    vif = [ 'bridge=xenbr0' ]

However, if there is only one bridge in existence on your machine, the
vif-bridge script will automatically use that. 

Please note that the vif-bridge script does *not* create bridges - it
just adds and removes interfaces from bridges that already exist. The
fact that you can't start a DomU suggests that there is a bug in
vif-script as far as Slackware is concerned.

And the following is also a worry. It suggests to me that there is a bug
in bridge-script as far as Slackware is concerned. It looks to me that
your very act of trying to check the status of the bridge with
"./network-bridge status" is what is responsible for corrupting the
bridge. Any chance you can check the status of the bridge with 
"brctl show" immediately before you do this other check?
>
> Another thing I try.
> I set the line in the config.sxp back to (network-script network-bridge)
> 
> When I do this, I find something strange too:
> root@vm01:/etc/xen/scripts# ./network-bridge status
> ============================================================
> 5: eth1: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue
>    link/ether 00:30:48:33:3b:75 brd ff:ff:ff:ff:ff:ff
>    inet 10.201.1.100/24 scope global eth1
> 12: xenbr1: <BROADCAST,NOARP,UP> mtu 1500 qdisc noqueue
>    link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff
> 
> bridge name     bridge id               STP enabled     interfaces
> xenbr1          8000.feffffffffff       no              vif0.1
>                                                        peth1
> 
> 10.200.1.0/24 dev eth0  proto kernel  scope link  src 10.200.1.100
> 10.201.1.0/24 dev eth1  proto kernel  scope link  src 10.201.1.100
> 127.0.0.0/8 dev lo  scope link
> default via 10.200.1.1 dev eth0  metric 1
> 
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags Metric Ref    Use
> Iface
> 10.200.1.0      0.0.0.0         255.255.255.0   U     0      0        0 eth0
> 10.201.1.0      0.0.0.0         255.255.255.0   U     0      0        0 eth1
> 127.0.0.0       0.0.0.0         255.0.0.0       U     0      0        0 lo
> 0.0.0.0         10.200.1.1      0.0.0.0         UG    1      0        0 eth0
> ============================================================
>
> 
> It seems it's creating a xenbr1 because it thinks that's my outgoing
> interface. So I guess your suggestion should be followed, and I have to add
> something to the xend-config.sxp file to get things right.
> 

This stuff is just wierd.

> If this has to do with my distribution (Slackware), please just say that. I
> don't like to switch, but if necessary, I'll do that. I tried ubuntu
> 6.0664-bit, which worked fine, but not all my machines are 64-bit.
> With ubuntu
> 6.06 32-bit I ran into big problems because of the TLS-libs, which should be
> recompiled with some options (something about no segments). I didn't succeed
> doing that. I did succeed recompiling the glibc on my slackware box, so now
> I'm using this.
> But if all my problems would be resolved by choosing some other
> distribution, please let me know. I'm working on this Xen-setup for more
> than two weeks now, and I just don't know it anymore. I considered moving to
> the commercial version of xen, but my server is not supported by them (3ware
> 9650 controller). I'm also willing to pay someone to get installation
> support, I just want it to work :(
> 

Okay, I don't want to start a troll here, but... Ubuntu is great on the
desktop - really great. However, if you take Ubuntu off the desktop you
are using Debian - and if you're going to use Debian then do it
directly. If I was recommending a distro to you for a production
environment, I'd recommend you go with Debian Etch.

This said, I think there is a lot to be said for sticking with what you
know. Debian has a large learning curve and it's not one you want to
climb in a production enviroment IMO. But whatever you decide to do from
here, I certainly think that you should increase you options by
learning a second system and learning it well.

In answer to your question: Yes, I definitely think that you can get xen
working with little or no fuss by switching to another distribution. 
However, I don't think that the problems you are having are really 
that serious. It's just likely that the shell scripts under
/etc/xen/scripts need a bit of tweaking to get things working. In fact,
it would be a simple matter to just by-pass the xen scripts altogether
and just use your own. This is what I have done on one of my boxes.
There are no really serious problems here, just misunderstandings.

Anyway, I'll ping you off-line about taking a closer look at your setup.

jez

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users