[Pkg-xen-devel] dom0 kernel for xen 3.2

[Pasi Kärkkäinen]

On Thu, Jan 24, 2008 at 07:21:07PM +0300, Nikita V. Youshchenko wrote:
> > > I've read somewhere that 2.6.18-5-xen kernel from etch is not
> > > compatible with xen 3-1, and won't boot with it.
> > > Is that true?
> >
> > I don't think that's true.. a friend of mine installed debian xen 3.1.2
> > two days ago (64bit version) and booted dom0 with 2.6.18-5-xen kernel.
> >
> > > What about xen 3.2 ?
> >
> > I think it should work, but I've not tried it yet.
> >
> > > I'm currently running several xen-based servers, and there are some
> > > issues with those. I would like to check if situation is better with
> > > later xen releases.
> >
> > Problems with what? :)
> 
> We have a domain that runs a desktop server: about 50 Xvnc processes
> each running a KDE desktop, with 15-20 users connected using vncviewer
> from thin clients at patricular time.
> Sometimes (10-20 times a day) network connection to this domain freezes,
> and user desktops freeze for 5-30 seconds (then unfreeze). This is harmless,
>  but annoys users a lot.
> 
> Here is example tcpdump log for such an event. Tcpdump was executed inside the domain.
> ...
> 13:33:38.134818 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9272, length 64
> 13:33:38.134861 IP desktopvm > zigzag.lvknet: ICMP echo reply, id 52019, seq 9272, length 64
> 13:33:39.138863 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9273, length 64
> 13:33:39.138925 IP desktopvm > zigzag.lvknet: ICMP echo reply, id 52019, seq 9273, length 64
> 13:33:40.142855 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9274, length 64
> 13:33:41.146918 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9275, length 64
> 13:33:42.150870 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9276, length 64
> 13:33:43.154838 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9277, length 64
> 13:33:44.158854 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9278, length 64
> 13:33:45.158853 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9279, length 64
> 13:33:46.158828 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9280, length 64
> 13:33:47.158880 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9281, length 64
> 13:33:48.158845 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9282, length 64
> 13:33:49.158799 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9283, length 64
> 13:33:50.158898 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9284, length 64
> 13:33:51.158799 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9285, length 64
> 13:33:52.158758 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9286, length 64
> 13:33:53.158844 IP zigzag.lvknet > desktopvm: ICMP echo request, id 52019, seq 9287, length 64
> 13:33:54.010610 IP desktopvm > zigzag.lvknet: ICMP echo reply, id 52019, seq 9274, length 64
> 13:33:54.010619 IP desktopvm > zigzag.lvknet: ICMP echo reply, id 52019, seq 9275, length 64
> 13:33:54.010636 IP desktopvm > zigzag.lvknet: ICMP echo reply, id 52019, seq 9276, length 64
> 13:33:54.010640 IP desktopvm > zigzag.lvknet: ICMP echo reply, id 52019, seq 9277, length 64
> 13:33:54.010647 IP desktopvm > zigzag.lvknet: ICMP echo reply, id 52019, seq 9278, length 64
> 13:33:54.010660 IP desktopvm > zigzag.lvknet: ICMP echo reply, id 52019, seq 9279, length 64
> 13:33:54.010687 IP desktopvm > zigzag.lvknet: ICMP echo reply, id 52019, seq 9280, length 64
> 13:33:54.010698 IP desktopvm > zigzag.lvknet: ICMP echo reply, id 52019, seq 9281, length 64
> ...
> 
> In this trace, during freeze, incoming packets continue to arrive, but
> outgoing are not sent.
> 
> On one of other traces, I've seen that packets are still both arrived and sent
> by the domain, but are frozen on the bridge in dom0.
> 
> This looks like some misinteraction between netfront inside domain,
> xen netfront<->netback transport, netback in dom0, and probably linux bridge.
> 

With what xen and kernel versions does this happen (both dom0 and domU)? 32b or 64b?

-- Pasi