The Book of Xen

Applying the Debugger

If even the maximum-verbosity logging isn't enough, it's time to attack the problem at the Python level, with the debugger.

One investigation to try is to run the xend server in the foreground and watch its debug output. This will let you see somewhat more information than simply following the logs.

With current versions of Xen, the debug functionality is included in the releases.^[86] Enable the debug output with the following:

# export XEND_DEBUG=1
# export XEND_DAEMONIZE=0

# xend start

This will start xend in the foreground and tell it to print debug messages as it goes along.

You can also get copious debugging information for the XenStore by setting XENSTORED_TRACE=1 somewhere where xend's environment will pick it up, perhaps ...