Data Centers

Set bandwidth limits for Hyper-V VMs with Windows Server 2012

Consolidated infrastructures need limits at times. Rickatron shows an easy-to-use Hyper-V networking tip.
If you are considering Hyper-V with Windows Server 2012, there are a lot of options for the standalone hypervisor that make it easy to use, yet give you granular control. I came across the bandwidth management feature for Hyper-V on Windows Server 2012 (and actually also included with Windows 8 Pro with the Hyper-V feature enabled). This feature optionally sets limits on network bandwidth in terms of a minimum and maximum amount of megabytes per second (MBps). This option is set per VM and it is shown below:

Figure A

The bandwidth can be set for each VM

The bandwidth can be set for each VM. (Click to enlarge.)

The benefit here is that you may have very noisy virtual machines that consume a lot of bandwidth, and they can be stepped down yet still given an adequate amount of connectivity. If multiple virtual machines are in use on a Hyper-V host, and each of them have maximum values that all together exceed the bandwidth of the host's physical network connectivity on the External virtual switch, there would be network contention. The contention also would slow down the actual Hyper-V host's connectivity; so keep that in mind — especially if the Hyper-V host is a Windows Server 2012 system with the Hyper-V role added.

Hyper-V by itself (without Failover Cluster Manager or System Center Virtual Machine Manager) doesn't offer too many configuration options for the virtual switch types (Internal, External and Private) within Hyper-V Manager. Having this granular option for each virtual machine is a nice and easy way to address networking limits if they are required for your virtual machines. The reverse perspective may be to set your most critical virtual machines to not have a limit, and the least critical ones to have a limit equivalent to 1 Gbps Ethernet (if the host has 10 Gbps) connectivity.

Do you see a use for individual VM bandwidth management options for Hyper-V? How would you use this feature? Share your comments below.


Rick Vanover is a software strategy specialist for Veeam Software, based in Columbus, Ohio. Rick has years of IT experience and focuses on virtualization, Windows-based server administration, and system hardware.

Editor's Picks