We had a little strange experience here. We had to copy something to our xen image. It was done while the domU was down, mounting using the loopback device. After we had finished the job, unmounted, and restarted the domU, we had no eth0. Got an error message in the bootup. I thought something had gone really wrong, and that we no more had network access in this particular domU. After checking things out, there was still an ethernet device, however now it''s listed as eth3 inside the domU. Is there a way to control what the virtual ethernet device should be named inside the virtual domU? Given the current config it could for instance all of a sudden turn up as eth2, so it would be nice to be able to say that it should ALWAYS be known as eth0 Anyone who has any suggestions? (I''ve attached the current config, only diffence from the actual config is that the real IP is not specified, there is only one bridge in use, and eth3 does work exactly like the previous eth0 did) Thanks! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> -----Original Message----- > From: xen-users-bounces@lists.xensource.com > [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of > Rune Elvemo > Sent: 14 March 2007 15:15 > To: Xen users > Subject: [Xen-users] in domU eth0 is now eth3? > > We had a little strange experience here. We had to copy > something to our > xen image. It was done while the domU was down, mounting using the > loopback device. > After we had finished the job, unmounted, and restarted the > domU, we had > no eth0. Got an error message in the bootup. I thought something had > gone really wrong, and that we no more had network access in this > particular domU. > > After checking things out, there was still an ethernet device, however > now it''s listed as eth3 inside the domU. Is there a way to > control what > the virtual ethernet device should be named inside the virtual domU? > > Given the current config it could for instance all of a > sudden turn up > as eth2, so it would be nice to be able to say that it should > ALWAYS be > known as eth0 > > Anyone who has any suggestions? > > (I''ve attached the current config, only diffence from the > actual config > is that the real IP is not specified, there is only one bridge in use, > and eth3 does work exactly like the previous eth0 did)I believe the latest 3.0.4-1 has a fix for this. Certainly, it''s been fixed in xen unstable. -- Mats> > Thanks! >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Yeah I''ve had this too :( The way I got around it was to install a package (apt-get in Debian) called ifrename in the domU. Specify a MAC address in your domU config so that dom0 won''t choose one for you: vif = [ ''type=netfront, mac=00:16:3e:00:02:01'' ] Or similar (prefix of 00:16:3e is reserved for Xen). Then in the domU do this: echo ''eth0 mac 00:16:3e:00:02:01'' > /etc/iftab Next time you boot your domU it should always have that MAC on eth0. Hope this helps, Jim ----- Original Message ----- From: "Daire Byrne" <Daire.Byrne@framestore-cfc.com> To: "Jim Vanns" <Jim.Vanns@framestore-cfc.com> Sent: 15 March 2007 10:47:32 o''clock (GMT) Europe/London Subject: Fwd: [Xen-users] in domU eth0 is now eth3? Maybe you have the answer for this guy? ;-) Daire ----- Forwarded Message ----- From: "Rune Elvemo" <rune.elvemo@3way.no> To: "Xen users" <xen-users@lists.xensource.com> Sent: 14 March 2007 15:15:16 o''clock (GMT) Europe/London Subject: [Xen-users] in domU eth0 is now eth3? We had a little strange experience here. We had to copy something to our xen image. It was done while the domU was down, mounting using the loopback device. After we had finished the job, unmounted, and restarted the domU, we had no eth0. Got an error message in the bootup. I thought something had gone really wrong, and that we no more had network access in this particular domU. After checking things out, there was still an ethernet device, however now it''s listed as eth3 inside the domU. Is there a way to control what the virtual ethernet device should be named inside the virtual domU? Given the current config it could for instance all of a sudden turn up as eth2, so it would be nice to be able to say that it should ALWAYS be known as eth0 Anyone who has any suggestions? (I''ve attached the current config, only diffence from the actual config is that the real IP is not specified, there is only one bridge in use, and eth3 does work exactly like the previous eth0 did) Thanks! -- James Vanns Systems Programmer Framestore CFC Ltd. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Wed, Mar 14 ''07 at 16:15, Rune Elvemo wrote:> We had a little strange experience here. We had to copy something to our > xen image. It was done while the domU was down, mounting using the > loopback device. > After we had finished the job, unmounted, and restarted the domU, we had > no eth0. Got an error message in the bootup. I thought something had > gone really wrong, and that we no more had network access in this > particular domU.You don''t mention what distribution you''re using for the domU. Debian Etch (4.0) has the unfortunate habbit of remembering what MAC address an ethernet card had. So on the normal Xen 3.0.3 (as shipping with etch) setup, where you get a new MAC on every boot, you start with an eth0 but after 4 reboots have only an eth4 ... (the MACs are recorded in /etc/udev/rules.d/z25-persistent-net (path from memory) -- /"\ 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 - ] / \ [ 3. Reply to the list - 4. Read the archive *before* you post ] _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Goetz Bock wrote:> On Wed, Mar 14 ''07 at 16:15, Rune Elvemo wrote: >> We had a little strange experience here. We had to copy something to >> our xen image. It was done while the domU was down, mounting using >> the loopback device. >> After we had finished the job, unmounted, and restarted the domU, we >> had no eth0. Got an error message in the bootup. I thought something >> had gone really wrong, and that we no more had network access in this >> particular domU. > You don''t mention what distribution you''re using for the domU. > > Debian Etch (4.0) has the unfortunate habbit of remembering what MAC > address an ethernet card had. So on the normal Xen 3.0.3 (as shipping > with etch) setup, where you get a new MAC on every boot, you start > with an eth0 but after 4 reboots have only an eth4 ... > (the MACs are recorded in /etc/udev/rules.d/z25-persistent-net (path > from memory)There''s a reason for this sort of thing. Associating specific network ports with specific hardware can be.... awkward, since compiling some modules directly into a kernel or loading them after boot or even subtle differences in the modules themselves can re-order the network ports. This was even worse with wireless ports in the picture. And it''s deadly on a firewall box, since the firewall rules may be very different for different ports. So in many distributions, the network port is associated not only with a specific module, but with a specific MAC address to keep things consistent. Voila, no hopping ports. But Xen''s habit of auto-assigning randomized MAC addresses can trip over this. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users