Re: strange guest slowness after some time

[Felix Leimbach <felix.leimbach@gmx.net>]

Tomasz Chmielewski wrote:
> Tomasz Chmielewski schrieb:
>> Avi Kivity schrieb:
>>> packet counters are will within 32-bit limits.  byte counters not so 
>>> interesting.
>>
>> Ah OK.
>> I did only byte overflow.
>>
>> Packet overflow will take much longer. It's one of these very rare 
>> cases where setting very small MTU is useful...
>
> OK, another bug found.
>
> Set your MTU to 100.
>
> On two hosts, do:
>
> HOST1_MTU1500# dd if=/dev/zero | ssh manager@HOST2 dd of=/dev/null
> HOST2_MTU100# dd if=/dev/zero | ssh manager@HOST1 dd of=/dev/null
>
> HOST2 with MTU 100 will crash after 10-15 minutes (with packet count 
> still not overflown).
>
Intersting. What are the packet counter at crash time (roughly)?

My - currently running - test is:

Guest 1 (Linux):
MTU 150
# cat /dev/zero | nc <guest2ip> 7777

Guest 2 (Windows 2003 Server):
MTU: 1500
# nc -l -p 7777 > NUL

My packet are currently at 63 million without a problem - yet.