Pasi Kärkkäinen
2006-Mar-18 13:04 UTC
[Xen-devel] Xen3 domU network packet loss (udp iperf)
Hi! Please check out this URL: http://nrg.joroinen.fi/xen-ploss.txt There you have UDP iperf results to and from domU and dom0. It seems xen causes packet loss to domU''s.. dom0 works well without packet loss. Is this known problem? I''m using bridged networking with xen. Both the xen box, and the external non-xen box were P4 3.0+ GHz, using gigabit NIC''s (tg3 and e1000). in the xen box, all the physical network interfaces (tg3) have rx and tx checksumming on. I''m using xen 3 unstable from 2006-02-04. -- Pasi _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Pasi Kärkkäinen
2006-Mar-21 07:50 UTC
Re: [Xen-devel] Xen3 domU network packet loss (udp iperf)
And you won''t notice this packet loss with TCP, because TCP automatically re-transmits the missing packets.. TCP speed does suffer, however. Others seeing this? - Pasi On Sat, Mar 18, 2006 at 03:04:13PM +0200, Pasi Kärkkäinen wrote:> Hi! > > Please check out this URL: http://nrg.joroinen.fi/xen-ploss.txt > > There you have UDP iperf results to and from domU and dom0. > > It seems xen causes packet loss to domU''s.. dom0 works well without packet > loss. > > Is this known problem? I''m using bridged networking with xen. > > Both the xen box, and the external non-xen box were P4 3.0+ GHz, using > gigabit NIC''s (tg3 and e1000). > > in the xen box, all the physical network interfaces (tg3) have rx and tx > checksumming on. > > I''m using xen 3 unstable from 2006-02-04. > > -- Pasi >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Andrew D. Ball
2006-Mar-22 23:44 UTC
Re: [Xen-devel] Xen3 domU network packet loss (udp iperf)
I wonder if this is why I''ve never seen a domU kernel finish booting with ip="dhcp" in the Python configuration file. This translates to an "ip=:::::eth0:dhcp" kernel parameter, so the domU seems to be using the DHCP client embedded in the Linux kernel. It always times out for me, but I haven''t found time to dig deeper into what''s going wrong. Has anyone else had better luck? Thanks for your help. Andrew ============Andrew D. Ball <aball@us.ibm.com> Pasi Kärkkäinen wrote:> And you won''t notice this packet loss with TCP, because TCP automatically > re-transmits the missing packets.. TCP speed does suffer, however. > > Others seeing this? > > - Pasi > > On Sat, Mar 18, 2006 at 03:04:13PM +0200, Pasi Kärkkäinen wrote: > >>Hi! >> >>Please check out this URL: http://nrg.joroinen.fi/xen-ploss.txt >> >>There you have UDP iperf results to and from domU and dom0. >> >>It seems xen causes packet loss to domU''s.. dom0 works well without packet >>loss. >> >>Is this known problem? I''m using bridged networking with xen. >> >>Both the xen box, and the external non-xen box were P4 3.0+ GHz, using >>gigabit NIC''s (tg3 and e1000). >> >>in the xen box, all the physical network interfaces (tg3) have rx and tx >>checksumming on. >> >>I''m using xen 3 unstable from 2006-02-04. >> >>-- Pasi >> > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Pasi Kärkkäinen
2006-Mar-28 15:39 UTC
Re: [Xen-devel] Xen3 domU network packet loss (udp iperf)
On Wed, Mar 22, 2006 at 06:44:52PM -0500, Andrew D. Ball wrote:> I wonder if this is why I''ve never seen a domU kernel finish booting > with ip="dhcp" in the Python configuration file. > > This translates to an "ip=:::::eth0:dhcp" kernel parameter, so the domU > seems to be using the DHCP client embedded in the Linux kernel. > > It always times out for me, but I haven''t found time to dig deeper into > what''s going wrong. > > Has anyone else had better luck? >I also noticed that when doing both the incoming and outgoing transfers simultaneously, the incoming speed to domU is 1/2 of the speed of outgoing speed (or even lower). with iperf "Do a bidirectional test simultaneously" test: outside -> domU: 175 Mbits/sec domU -> outside: 392 Mbits/sec What could explain that? - Pasi> Thanks for your help. > Andrew > ============> Andrew D. Ball <aball@us.ibm.com> > > Pasi Kärkkäinen wrote: > >And you won''t notice this packet loss with TCP, because TCP automatically > >re-transmits the missing packets.. TCP speed does suffer, however. > > > >Others seeing this? > > > >- Pasi > > > >On Sat, Mar 18, 2006 at 03:04:13PM +0200, Pasi Kärkkäinen wrote: > > > >>Hi! > >> > >>Please check out this URL: http://nrg.joroinen.fi/xen-ploss.txt > >> > >>There you have UDP iperf results to and from domU and dom0. > >> > >>It seems xen causes packet loss to domU''s.. dom0 works well without packet > >>loss. > >> > >>Is this known problem? I''m using bridged networking with xen. > >> > >>Both the xen box, and the external non-xen box were P4 3.0+ GHz, using > >>gigabit NIC''s (tg3 and e1000). > >> > >>in the xen box, all the physical network interfaces (tg3) have rx and tx > >>checksumming on. > >> > >>I''m using xen 3 unstable from 2006-02-04. > >> > >>-- Pasi > >> > > > > > >_______________________________________________ > >Xen-devel mailing list > >Xen-devel@lists.xensource.com > >http://lists.xensource.com/xen-devel > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel