Description of problem:

When taking baby steps on getting a xen client going, the error 
message 'Error: Device 769 (vbd) could not be connected. Hotplug scripts not 
working.' appears:

[root@buran xen]# xm create -c myxen vmid=1
Using config file "myxen".
Error: Device 769 (vbd) could not be connected. Hotplug scripts not working.

'myxen' is the stock xmexample1 script - only thing changed is the name of the 
kernel image.  And since my disks are sda and sdb, the default disk drive 
didn't exist.

Suggest a 'specify an existing disk, dummy' error message.