What format is the backup data stored in?
The reason this is important is that there may be a way to create a backup without booting to the LiveCD. I agree that scheduling downtime for the creation of a backup is unreasonable. The alternatives I can think of are:
1. Find a way of making a compatible backup file by other means from within other OS environments.
2. Run the LiveCD in a VirtualBox and create the backup without shutting down.