[CentOS-virt] Windows Xen VM's have high guest CPU usage and poor performance
pasik at iki.fi
Thu Jan 21 21:30:45 UTC 2010
On Thu, Jan 21, 2010 at 11:28:43PM +0200, Pasi Kärkkäinen wrote:
> On Thu, Jan 21, 2010 at 11:37:02AM -0500, Ryan Pugatch wrote:
> > Eric Searcy wrote:
> > >> The install worked beautifully except that my VM now has an ip assigned
> > >> of 192.168.122.186 which I'm guessing is in relation to virbr0 which is
> > >> 192.168.122.1 on the host (and subsequently has no internet
> > >> connectivity). Is it possible for me to pass through to my network like
> > >> before so my VM can have an ip on my local network?
> > >
> > > Unless you specify a bridge in the xen conf file, it uses the first one
> > > it finds alphabetically, I believe. Do you use virbr0 for anything
> > > else? As an easy way of making sure xenbr0 is used, I removed the file
> > > /etc/libvirt/qemu/networks/autostart/default.xml which was auto-starting
> > > this DHCP (and NATted?) bridge, and I only was using direct access. But
> > > you can also make it explicit on the interface line, one of my HVM VMs
> > > has the following:
> > >
> > > vif = [ 'mac=00:16:3e:0a:4c:d2, bridge=xenbr0' ]
> > >
> > > Eric
> > That worked.. thanks Eric. However, even with the GPLPV drivers, I am
> > seeing a lot of CPU usage when I do anything on the Windows VM. It
> > isn't just the guest that is reporting CPU usage, though. When I watch
> > xm top, the CPU usage jumps on that VM. Not really sure what else can
> > be done to improve performance.
> Check these tips:
> And also this:
Oh, one more thing.. is it only the guest VM taking cpu time
when you monitor with "xm top"?
Do you have the latest service packs installed in the guest?
Have you tried monitoring the performance from inside the guest,
to figure out what takes cpu time there?
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