debugging udev for runnin Xen

[Tapas Mishra]

Hi,
I am trying to run Xen-4.0 on one of our machines.Where I had got some
errors in creating virtual machines on Xen.
I am trying to debug this problem and want to know
 how to make sure if udev is running (some related stuff)
if some one can give a relevant link.
I Googled it
http://www.google.co.in/search?hl=en&client=ubuntu&hs=9ER&channel=cs&q=how+to+check+udev+is+running+ubuntu&aq=f&aqi=&aql=&oq=
but I think I did not reached any thing useful.