[fedora-virt] Poor performace for e1000 and other fully virtualized netcard

[Amit Shah]

On (Fri) 06 Sep 2013 [07:40:52], Ján ONDREJ (SAL) wrote:
> On Fri, Sep 06, 2013 at 01:06:04AM +0530, Amit Shah wrote:
> > On (Thu) 05 Sep 2013 [21:21:00], Ján ONDREJ (SAL) wrote:
> > > On Fri, Sep 06, 2013 at 12:22:45AM +0530, Amit Shah wrote:
> > > > On (Thu) 05 Sep 2013 [15:26:52], Ján ONDREJ (SAL) wrote:
> > > > 
> > > > > As described in other bug, virtio net driver has time skew problems, so
> > > > > I can't use it. :-(
> > > > 
> > > > Please share details -- link to bug report or mail list post.
> > > 
> > > Thread 2 month ago here:
> > > 
> > >   https://lists.fedoraproject.org/pipermail/virt/2013-July/003714.html
> > > 
> > > or rhbz:
> > > 
> > >   https://bugzilla.redhat.com/show_bug.cgi?id=982459
> > > 
> > > Btw, latest 3.9 kernel for fc18 works well:
> > >   kernel-3.9.11-200.fc18.x86_64  -  fast network speed
> > 
> > That thread and bug says you have problems with virtio and Windows
> > guests.  You're here saying the kernel version matters.  Does this
> > mean that the host kernel version matters for you when you use e1000
> > or virtio-net cards with Windows guests?
> 
> Time skew problems are not kernel specific, this bug is prensent always.
> But this happens only if virtio-net windows driver is installed in guest.
> 
> Slow network for e1000 and possibly other network cards is kernel specific.
> Kernels 3.10+ on hosts.

Can you try Linux guests?

> Btw, another bug in 3.9.11. One guest stopped to communicate on
> ethernet. When trying to restart it, shutdown completed, but qemu process is
> still running in "D" (dead) state on host. Unable to kill it. :-(
>
> Which Fedora kernel should be fully functional? :-)
> 
> At our university we are using Fedora host over years, using mostly linux
> guests, but also some windows. My problems started with 3.10 kernels.
> I don't remember, which 3.9 kernel I used before.

Could also be something related to your setup; haven't seen such bugs
elsewhere.

		Amit