Re: Strange network behaviour

Uri Lublin
2007-12-05T11:46:46Z

Mike wrote:
> You can download the requested trace at
> http://www.eliteserver.biz/trace.tar.gz
>
> the peaks were around 12:04:30
>
> Mike
>
> Avi Kivity schrieb:
>
>> Mike wrote:
>>
>>> Avi Kivity schrieb:
>>>
>>>> Mike wrote:
>>>>
>>>>> Now I noticed a strange behaviour.
>>>>> I have a gameserver running in a guest os. No problems on performance
>>>>> side, really fast.
>>>>> The only thing, when I make a ping test after unspecific time periods I
>>>>> get this: (this peaks are even there if the gameserver isn't running)
>>>>>
>>>>>
>>>>> As you can see, no peaks.
>>>>> Example of start command from a guest:
>>>>> kvm -hda apache.img -hdb apache_storage.img -m 512 -boot c -net
>>>>> nic,vlan=0,macaddr=00:16:3e:00:00:01,model=rtl8139 -net tap -nographic
>>>>> -daemonize
>>>>>
>>>>> Here the pings from the guest started with the command line listed above:
>>>>>
>>>>> Reply from 195.24.77.171: bytes=32 time=37ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=37ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=97ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=60ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=186ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=363ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=368ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=972ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=673ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=1133ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=1198ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=1881ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=2341ms TTL=57
>>>>> Reply from 195.24.77.171: bytes=32 time=2401ms TTL=57
>>>>>
>> Ok. How long does it take for the latency to appear? If it isn't too
>> long, please run kvm with
>>
>> strace -fF -ttT -o /tmp/trace kvm ...
>>
>> Note the time that latency appears so we can correlate with the logs.
>> Be aware the logs can be quite large, so make sure you have some disk
>> space ready.
>>
>
Does using a different clock helps ( add "-clock hpet" or "-clock rtc"
or "-clock unix" to kvm command line) ?