Re: VM networking stops working

[Mike <mike-kcIQ9yavhvsV/sYkb9DZNQ@public.gmane.org>]

Izik Eidus schrieb:
> Mike wrote:
>> Izik Eidus schrieb:
>>  
>>> Mike wrote:
>>>    
>>>> Izik Eidus schrieb:
>>>>  
>>>>      
>>>>> Mike wrote:
>>>>>           
>>>>>> Hello,
>>>>>> I have a problem with my virtual machines. I am using kvm53
>>>>>> on an AMD Athlon(tm) 64 X2 Dual Core Processor 5000+.
>>>>>> As distribution I use Ubuntu server 7.10.
>>>>>> As kernel I use Linux 2.6.22-14-server #1 SMP Sun Oct 14 22:09:15 
>>>>>> GMT 2007 x86_64 GNU/Linux.
>>>>>>
>>>>>> I have 3 different vms running. At the beginning they all work 
>>>>>> without a problem.
>>>>>> Then, after one moment to another one or more stop working.
>>>>>> I did a ping test to all the machines, the vm with the failure 
>>>>>> stops pinging.
>>>>>> The result from external ping: Destination host unreachable.
>>>>>> The same result from a ping onto the main server.
>>>>>>
>>>>>> Here are my configuration files:
>>>>>> cat /etc/qemu-ifup
>>>>>> #!/bin/sh
>>>>>> /sbin/ifconfig $1 0.0.0.0 promisc up
>>>>>> /usr/sbin/brctl addif br0 $1
>>>>>> sleep 2
>>>>>> ------------------------------------------------------------------------ 
>>>>>>
>>>>>> cat /etc/network/interfaces
>>>>>> auto lo
>>>>>> iface lo inet loopback
>>>>>>
>>>>>> auto br0
>>>>>> iface br0 inet static
>>>>>> address 195.24.77.169
>>>>>> netmask 255.255.255.0
>>>>>> gateway 195.24.77.1
>>>>>> bridge_ports eth0
>>>>>> bridge_stp off
>>>>>> bridge_maxwait 5
>>>>>> ------------------------------------------------------------------------ 
>>>>>>
>>>>>> I use scripts for starting the vms:
>>>>>> kvm -hda apache.img -hdb apache_storage.img -m 512 -boot c -net 
>>>>>> nic,vlan=0,macaddr=00:16:3e:00:00:01 -net tap -nographic -daemonize
>>>>>> kvm -hda postfix.img -m 512 -boot c -net 
>>>>>> nic,vlan=0,macaddr=00:16:3e:00:00:12 -net tap -nographic -daemonize
>>>>>> kvm -hda openvpn.img -m 256 -boot c -net 
>>>>>> nic,vlan=0,macaddr=00:16:3e:00:00:03 -net tap -nographic -daemonize
>>>>>> ------------------------------------------------------------------------ 
>>>>>>
>>>>>> The tapN devices are being created at the startup of the vms.
>>>>>>
>>>>>> When I run dmesg I have this:
>>>>>> [  112.390943] br0: port 2(tap1) entering learning state
>>>>>> [  112.391919] br0: port 3(tap0) entering learning state
>>>>>> [  112.397605] br0: port 4(tap2) entering learning state
>>>>>> [  122.674313] tap0: no IPv6 routers present
>>>>>> [  122.729185] tap1: no IPv6 routers present
>>>>>> [  122.843901] tap2: no IPv6 routers present
>>>>>> [  123.336081] kvm: emulating exchange as write
>>>>>> [  127.367940] br0: topology change detected, propagating
>>>>>> [  127.367949] br0: port 4(tap2) entering forwarding state
>>>>>> [  127.362971] br0: topology change detected, propagating
>>>>>> [  127.362977] br0: port 2(tap1) entering forwarding state
>>>>>> [  127.362978] br0: topology change detected, propagating
>>>>>> [  127.362980] br0: port 3(tap0) entering forwarding state
>>>>>>
>>>>>> No indication of a problem, nowhere in the log files.
>>>>>>
>>>>>> I don't know if the vms are freezing, or the network forwarding 
>>>>>> stops working.
>>>>>> I also activated "net.ipv4.conf.default.forwarding=1"
>>>>>>
>>>>>> I googled days for that problem, but without a result.
>>>>>> I hope that maybe you have a solution for this problem. That 
>>>>>> would be great, because I prefer using kvm instead of other 
>>>>>> virtualization systems.
>>>>>>
>>>>>> Thank you very much in advance,
>>>>>> Greetings from Luxembourg.
>>>>>>
>>>>>> Have a nice day,
>>>>>> Mike
>>>>>>                 
>>>>> it might be not the network that die, but the whole vm
>>>>> can you run the vms with -vnc ? (first vm -vnc :1 secoend vm -vnc 
>>>>> :2 third vm -vnc :3)
>>>>> and try to connect to them with vncviewer and see if they are alive?
>>>>>
>>>>>             
>>>> Thank you for your reply.
>>>> I can't connect to the vm if it has died, even with vnc. I tried 
>>>> this already, no reply from the host.
>>>> I don't have physical access to the server because its located in a 
>>>> dc. Only ssh to the host.
>>>>         
>>> ok this mean there is bug in kvm for amd and it not realted to the 
>>> network
>>> what is the guest that you use? is it 64/32?
>>>
>>>     
>> I'm using Debian Etch 32 Bit for all guests
>> with Kernel Linux apache 2.6.18-5-486 #1 Tue Oct 2 23:38:54 UTC 2007 
>> i686 GNU/Linux
>>
>> ------------------------------------------------------------------------- 
>>
>>   
> ok but what more interesting me is:
> if you run just one vm
> is it work?
Yes. If I run only 1 vm, it runs days without problems.
I have sometimes have peaks in reply time from the guest.
e.g.
bytes=32 time=34ms TTL=57
bytes=32 time=34ms TTL=57
bytes=32 time=119ms TTL=57
bytes=32 time=400ms TTL=57
bytes=32 time=540ms TTL=57
bytes=32 time=947ms TTL=57
bytes=32 time=754ms TTL=57
bytes=32 time=850ms TTL=57
bytes=32 time=925ms TTL=57
bytes=32 time=2032ms TTL=57
bytes=32 time=897ms TTL=57
bytes=32 time=197ms TTL=57
bytes=32 time=34ms TTL=57
bytes=32 time=34ms TTL=57

but if I ping the host server the same time, the reply time is normal, 
around 34ms

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