Re: [Xen-users] XEN not working after reboot

[Rudi Ahlers <Rudi@xxxxxxxxxxx>]

On Fri, Jul 19, 2013 at 10:09 AM, Ian Campbell <Ian.Campbell@xxxxxxxxxx> wrote:
> Please keep the list in the loop. Re-adding CC.

Sorry, forgot to hit "Reply all".


>
> On Fri, 2013-07-19 at 09:51 +0200, Rudi Ahlers wrote:
>> Yes, this server has been running XEN for about 3 years now. It was
>> rebooted 87 days ago, if I remember correctly for some updates. This
>> is an active XEN server with 3 XEN domU virtual machines service
>> websites to clients on the internet.
>
> It seems entirely possible to me that some reconfiguration in the
> previous 87 days wasn't applied in a way which would survive a reboot.

I've always relied on "yum update" for updates and haven't run into
this kind of problem before. So, could it be that there's an upstream
bug, either in Scientifc Linux, or XEN's rpm's that could cause this?
I don't know where to search, since when I searched on the error I got
a lot of older posts relating to setting up XEN from scratch.

>
>> I've managed to "fix it" by manually creating the bridge, but then I
>> loose network connectivity to the remote server, and I don't have a
>> KVM connection to it. ... yet at least.
>
> I think that needs to be a priority for you unless there is a second
> Ethernet device available (in which case you may be able to fix eth0
> while logged in via eth1).
>

I'm still waiting for the DC to setup the KVM. They had to move "the
whole DC to a new building", including networking gear and a boat load
full of servers. And they're still busy moving everything, so for now
I have limited access and limited tools at my disposal.

I'll see if I can get another LAN cable hooked upto eth1 in the mean time.

>> These commands re-create the bridge, but then the host node's
>> networking doesn't work, although the VM's come up about 10 minutes
>> later. The thing is, I can't see what's going on after running "brctl
>> addif xenbr0 eth0". The firewall is disabled right now, so it's not
>> blocking anything.
>>
>> brctl addbr xenbr0
>> brctl stp xenbr0 off
>> brctl setfd xenbr0 0
>> ip link set xenbr0 up
>> brctl addif xenbr0 eth0
>
> None of these will transfer the ip configuration from eth0 to xenbr0,
> which is necessary for host networking to work.

Ok, so what else should I have done in order to transfer the IP
configuration from eth0 to xenbr0?
Right now I can ping the server but it doesn't respond to SSH, webmin
(used for other purposes, locked to internal IP's) or any of the other
network services

>
> If you are using a CentOS like environment then this should all have
> been done by your ifcfg scripts, or perhaps the network-bridge stuff if
> you are still using that.
>
> Have you compared this system's configuration with that of another
> working server?
>
>> I have googled that error, but the results I got all related to people
>> who just setup XEN and the bridge wasn't setup in the config. The
>> problem is, that it was setup, a few years ago already so the steps of
>> adding the bridge to the bridge-network script doesn't apply here.
>
> It sounds to me very much like someone has broken this configuration on
> this server and nobody noticed until it was rebooted. I would suggest
> starting from that assumption and double checking everything going
> through as you would an initial setup.
>
> Ian.

No one really works on the host servers, apart from doing a yum update
from time to time and I can't see any reason why anyone would have
touched the XEN configuration or setup at all. "why fix it if it aint
broken"?




-- 
Kind Regards
Rudi Ahlers
SoftDux

Website: http://www.SoftDux.com
Technical Blog: http://Blog.SoftDux.com
Cell: 082 554 7532
Fax: 086 268 8492

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