Recovery Mode can be helpful if you need to do certain task like operate on the VM with the disk unmounted or you need to reset a root password.
All of the following is done through XenCenter
To boot the VM into recovery mode all you have to do is
- Shutdown the VM
- Insert boot media i.e. (DVD, cd, iso image, etc.) into DVD Drive 1:
- Start VM in Recovery Mode. In the main menu click on VM –> Start/Shut Down –> Start in Recovery Mode
When the VM boots up it will boot off of whatever is in DVD Drive 1.