Hyper-V over SMB: SMB Bandwidth Limits

SMB is a huge topic since Windows Server 2012 and together with the concept of Converged Networking there was one very important features missing, and this was QoS (Quality of Service) for SMB traffic. With Windows Server 2012 R2 Microsoft addressed that and added a new feature called SMB Bandwidth Limits. SMB Bandwidth Limits allow you do separate different types of SMB traffic and limit them.

There are three different default types of SMB categories:

• Default – Access to File Servers for library storage, for example the System Center Virtual Machine Manager to copy files to the Hyper-V server.
• VirtualMachine – The traffic between the Hyper-V hosts and the storage of the Virtual Machines
• LiveMigration – In Windows Server 2012 Live Migration can make use of SMB and so you can also set a limit to Live Migration traffic

For example you could limit the Default SMB traffic and the Live Migration traffic and leave the Virtual Machine Storage traffic unlimited.

Enable SMB Bandwidth Limit

To set this up you have first to enable the feature over Server Manager or Windows PowerShell.

Server Manager:

PowerShell:

 
Install-WindowsFeature FS-SMBBW

Hot to configure SMB Bandwidth Limits

You can configure the SMB Bandwidth Limits via Windows Powershell

Set-SmbBandwidthLimit -Category LiveMigration -BytesPerSecond 125829120
 
Get-SmbBandwidthLimit
 
Remove-SmbBandwidthLimit -Category LiveMigration

Source: Graphic from Jose Barreto (Microsoft Corp.)