FYI, The Xen domain tck08 on selene.apache.org crashed yesterday.
'xm log' showed that the domain had indeed crashed and that the subsequent attempt to restart the domain had failed because the domain already existed.
When I looked, 'xm list' did not show tck08 as a domain that could be controlled (start, shutdown, etc).
I finally ended up running 'xm create /etc/xen/tck08.cfg'. This seems to have restarted the domain. I'm able to log in to tck08, and everything looks ok. So, hopefully it's back in service.
--kevan