Error: Device 768 (vbd) could not be connected. Hotplug scripts not working

When you try to start a Xen vps from solusVM, It wont get started. If you try to start from the backend, you may end up with following error.

# xm create /home/xen/vm123/vm123.cfg

          Using config file "/home/xen/vm123/vm123.cfg".          Error: Device 768 (vbd) could not be connected. Hotplug scripts not working.

Check the hotplug error log :

# tail /var/log/xen/xen-hotplug.log

If you get the following output :

         stat: cannot stat `/dev/xensan/vm123_img': No such file or directory
         Nothing to flush.

Activating the corresponding logical volumes for the vps will fix the issue.

# lvchange -ay /dev/xen**/vm123_img