Re: [Xen-devel] Question about xen network and strange happenings with migrating a node

[Kris <kris@xxxxxxxxxxxxxx>]

Hi Ian,

Thanks so much for the response.

The guest kernel is 2.6.32-71.29.1.el6.x86_64 on a CentOS 6.0 system. 

However, this happens on other versions of the kernel on a CentOS 5.X system. 
I've had it happen *anecdotally* on systems from CentOS 5.0-6.0.

I'll try to replicate this and attempt to issue 'xenstore-ls -fp'.

If there's anything else you or anyone can think of, please recommend them. 
Especially some sort of explanation of what those integers mean in the 
network-list?

Thanks again,
Kris



On 2012-02-09, at 8:11 AM, Ian Campbell wrote:

> On Wed, 2012-02-08 at 19:44 +0000, Kris wrote:
>> Hi,
>> 
>> I've been experiencing some issues with Xen-3.4.2-2.el5 (from gitco)
>> on CentOS 5.4 when migrating nodes from one physical node to another.
>> Each VM has 3 network interfaces (vifs).
>> 
>> When doing a live migration (xm migrate --live <params>) the network
>> of the migrated VM seems to go in to a very odd state when it's done
>> migrating. I've searched high and low for some documentation on what
>> the state, evt-ch,tx-/rx-ring-ref fields mean with their particular
>> integer values, but 1,-1,-1/-1 respectively seems to be indicative of
>> something that has gone badly. A state of 4 seems to indicate that the
>> interface is in a working state.
>> 
>> When doing a xm network-list VM on the node it is being migrated *to*
>> - in this case all of them are broken, but sometimes it's just one or
>> two interfaces are in this state.:
>> Idx BE     MAC Addr.     handle state evt-ch tx-/rx-ring-ref BE-path
>> 0   0  <REDACTED>   0     1      -1    -1   /-1      
>> /local/domain/0/backend/vif/2/0  
>> 1   0  <REDACTED>    1     1      -1    -1   /-1      
>> /local/domain/0/backend/vif/2/1  
>> 2   0  <REDACTED>    2     1      -1    -1   /-1      
>> /local/domain/0/backend/vif/2/2
>> 
>> The result is that the network interfaces with the output above do not
>> work.
>> 
>> Is there anything I can do to perhaps debug this better? Is there any
>> documentation I'm missing out that would explain this stuff? Any
>> troubleshooting help is appreciated. I've looked at the xend logs and
>> there doesn't seem to be anything indicative of why this is occurring.
> 
> There's a good chance this is a guest kernel issue. What sort of guests
> are they and what kernel version are they running? Is there anything in
> the guest kernel logs or on the guest console?
> 
> The output of "xenstore-ls -fp" after this has happened would also be
> potentially interesting.
> 
> Ian.
> 
> 


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