I05-01

A cloud computing environment leverages many fundamental technologies. One such technology is virtualization (hypervisor). At a high level, the hypervisor allows for a number of virtual machines to share the physical resources of a single physical machine. A large number of physical machines with hypervisors (host machines) could be networked together to form what is known as a cloud environment. A virtual machine that is hosted on a hypervisor is often referred to as a guest virtual machine.

The increase of a number of organizations leveraging the same physical host hypervisor for guest virtual machines opens up the opportunity for what is often referred to as side channel attacks. An example of a side channel attack within the cloud environment is the observation of a program’s memory access patterns to the shared processor cache. A technique that allows a virtual machine to accommodate increased resource needs or possibly defend itself from side channel attacks is migration. Migration is the process of moving a guest virtual machine from one physical host to another. Two migration types considered through experimentation are offline migration and cloning migration. To consider different migration types, a Denial of Service (DoS) scenario was created to increase the resource needs of a host to cause a migration from one physical host to another.

The DoS victim guest virtual machine was cloned. For this migration type, the completion time frame and guest virtual machine downtime are the same. A plot of the migration time in seconds for ten tests is shown below.

The DoS victim guest virtual machine was migrated by the controller by first being taken offline (shutdown) and then being moved before being brought back online. For this migration type, the completion time frame and guest system downtime are the same. A plot of the migration time in seconds for ten tests is shown below.