>I installed the latest Xen with linux-2.6.8.1 on
>my RedHat machine today. After "make-install" and
>restart, it runs well. When I edited the xmexample1
>file at minimun, including "kernel", "memory", "disk",
>"dhcp", and executed "xm create -f ./xmexample1
>vmid=1", there's an error. It says 
> "Error: Internal Server Error"
Have you started xend? ("xend start") 
I guess you have, but in this case I'd expect a load of 
output from xend after you type 'xm create...' - do you 
see anything?
One other thing to check is you have a /etc/xen/xmdefconfig 
(or to simply cp xmexampl to /etc/xen/xmdefconfig and then 
 try "xm create -c vmid=") 
cheers,
S.