[CentOS-virt] Windows Xen VM's have high guest CPU usage and poor performance
pasik at iki.fi
Thu Jan 21 12:03:04 UTC 2010
On Wed, Jan 20, 2010 at 10:18:06PM -0500, Ryan Pugatch wrote:
> Hello all,
> I have a PowerEdge 2950 that I am using to host Windows XP VM's under
> CentOS. I am experiencing poor performance in the Xen VM's. Any time I
> try to do something, the CPU usage (as reported by the Windows task
> manager) hits 100% for a few and then drops back down. This is causing
> the VM's to run sluggish and be quite annoying to use. Example.. I
> click IE.. cpu hits 100% and IE takes a bit to open. I go to a
> website.. 100%.. I click a link.. 100%. This is the case even if I only
> have one VM running.
> I now have 32 VM's running on the machine and dom0's cpu usage as
> reported by xm top is 622%. It seems like Xen is just performing poorly
> while handling these Windows VMs. Any suggestions? I have Windows VM's
> on other hardware (typically PowerEdge R905s and R710s and they seem ok).
> This 2950 is a decent machine.. 32G RAM, 2x Xeon E5405 (quad core) at
> 2ghz. And I'm only allocating 1 CPU and 768MB RAM for each VM.
> Sample config:
> name = "win01n"
> maxmem = 768
> memory = 768
> vcpus = 1
> builder = "hvm"
> kernel = "/usr/lib/xen/boot/hvmloader"
> boot = "c"
> pae = 1
> acpi = 1
> apic = 0
> localtime = 1
> on_poweroff = "destroy"
> on_reboot = "restart"
> on_crash = "restart"
> device_model = "/usr/lib64/xen/bin/qemu-dm"
> usbdevice = "tablet"
> sdl = 0
> vnc = 1
> vncunused = 0
> vncdisplay = "1"
> disk = [ 'file:/var/xen/running/win01n,ioemu:hda,w' ]
> vif = [ "bridge=xenbr0" ]
> serial = "pty"
> Thanks in advance for any insight!
So I take it you're not using PV-on-HVM drivers in Windows..
ie. windows is using the emulated NIC and IDE disk?
That will be slow.
You need to use PV drivers. See GPLPV drivers:
0.11.0.188 is the latest binary release.
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