[CentOS-virt] Windows Xen VM's have high guest CPU usage and poor performance

Thu Jan 21 21:39:31 UTC 2010
Ryan Pugatch <rpug at linux.com>

Pasi Kärkkäinen wrote:

> 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? 
> -- Pasi

The guest is running XP w/ SP3.  It is not just the guest VM taking cpu 
time.  Basically, whatever process I am doing hits 100% cpu usage in 
Windows.  If I open IE, it will use 100% cpu for a bit while it opens. 
If I try to click on a website, it will do it again.  Thus, it is 
causing a very sluggish session as it keeps pausing.  It isn't just IE, 
it's any program I try to use.  This CPU usage is reflected in xm top as 
both the guest's CPU% will hit 100% as will Dom-0.

I have done pretty much everything specified in the Xen Best Practices. 
  In fact, I have dedicated 4GB to Dom-0.


	- Ryan