CS-3310 - 07 Virtualization - I/O and the Cloud

Why must I/O be virtualized?

VMs issue sensitive device instructions.

How is disk virtualization done?

Hypervisor converts VM block accesses to a file or device.

How is network virtualization done?

Hypervisor emulates a virtual switch.

What is an I/O MMU used for?

Remap DMA addresses safely for VMs.

What problem does device passthrough solve?

Allows VM direct device access safely.

What is interrupt remapping?

Redirecting hardware interrupts to the correct VM.

Why do Type 2 hypervisors handle many devices easily?

They use host OS device drivers.

What is SR-IOV?

Hardware creating virtualized device functions for each VM.

What does SR-IOV trick VMs into believing?

They own the device exclusively.

What are virtual appliances?

Pre-packaged VMs containing full software stacks.

Why are virtual appliances useful?

Solve dependency and installation issues.

What are the five cloud characteristics?

On-demand, broad access, pooling, elasticity, measured service.

What is IaaS?

Virtual machines as a service.

What is PaaS?

Platform/environment delivered to users.

What is SaaS?

Application software delivered over the cloud.

What is live migration?

Moving a running VM with minimal downtime.

What is pre-copy migration?

Copying pages while VM runs, then briefly pausing to finish.

What is checkpointing?

Creating VM snapshots for rollback.