Here we assume that you have already created VM's device to link to desired ISO image you wish to boot from. The objective is to instruct XenServer's host virtual machine to boot from ISO CD/DVD image instead of default VDI disk. Failure to do so may result in following error message:
The bootloader returned an error
msg: Unable to find partition containing kernel
Administrative Local or Remote command line access to XenServer is required to complete this task.
Obtain VM UUID
Obtain UUID of the virtual machine you would like to boot from the ISO CD/DVD image. For example: