You work as an administrator at ABC.com. The ABC.com network consists of a single domain
named ABC.com. All servers in the ABC.com domain, including domain controllers, have Windows
Server 2012 installed.
ABC.com has a Hyper-V server, named ABC-SR13, which hosts multiple virtual machines.
You have enabled the use of Single-root I/O virtualization.
Which of the following is TRUE with regards to using Single-root I/O virtualization? (Choose all
that apply.)
A.
It maximizes network throughput, while minimizing network latency.
B.
It maximizes network throughput, as well as network latency.
C.
It avoids the virtual switch stack and allows the virtual machine direct access to the actual
network switch.
D.
It prevents the virtual machine from accessing the network switch directly.
I believe a better answer/understanding would be that SR IO avoids the virtual network adapter giving direct access to the network adapter.
@Louis, I agree. You’re not necessary giving better access to the “actual network switch” using SR-IOV, you’re just giving the VM direct hardware access to a physical network connection rather than the VM traveling the virtual switch then hitting the physical adapter provided by the host machine. Saying you’re giving better access to the actual network switch is presumptuous.
The idea is to maximize throughput and minimize latency.
SR-IOV gives an extra(!) Network access to a virtual machine. The Guest OS of Virtual machine with SR-IOV enabled (YES SR-IOV is managed per VM) can get direct access to a Special kind of Network-card that supports SR-IOV. This offloads the Hyper-visor layer when the Virtual Machine needs access outside the Host OS.
SR-IOV is a NONE-proprietary standard, which means that when you live-migrate a VM with SR-IOV enabled to another Host which also has special SR-IOV network-cards from another brand it will still be enabled! (all be it, during migration it will be disabled before migration of the VM itself, and re-enabled if the destination Host has SR-IOV stacks available.
For better understanding:
https://www.youtube.com/watch?v=hRHsk8Nycdg
https://www.youtube.com/watch?v=QZ-0sNj3pxk (watch this one twice(!))
https://www.youtube.com/watch?v=n0A6LPL6COE