The three levels that are included in instance isolation:

1. Networking isolation: it keeps the overall security of the ubuntu cloud system and keeps the network isolated from the user sight so that there will be less security issues.

2. OS isolation: it keeps the user away from the operating system changes. It provides Mandatory Access control (MAC) system that includes default scripts to provide the isolation from the user to the Operating system.

3. Hypervisor based machine isolation: it doesn’t allow the user to know what kind of hypervisor is used to provide the services which users have asked for. It provides intrinsic properties to hide its existence from the users of the cloud.