Slow performance on legacy Hyper-V

Posted on 16th November 2018

You may notice sluggish appliance performance when deploying the Foldr system on older Hyper-V hosts.  There is a known performance issue with all virtual machines running Windows Server hosts running 2008 & 2012 systems (including R2 editions) with the following scenario:

1.  Broadcom NetExtreme 1Gb network adapters assigned to handle virtual machine traffic
2. Outdated Broadcom drivers are installed
3.  Virtual Machine Queues (VMQs) are enabled

VMQs are designed to offload virtual network processing to the physical adapter hardware and in turn improve virtual machine performance.  When using certain branded network adapters and outdated drivers, VMQs are enabled by default by the driver (this is the case for Broadcom NetExtreme) and without other manual changes to the host system registry can dramatically degrade performance.

Note that other manufacturers such as Intel, do not automatically enable VMQs by default.

Always ensure your server is running the latest drivers available from the network vendor.  In the case of Broadcom, the latest available drivers should resolve the issue, however our recommendation is to disable the use of VMQs where possible on the physical network adapters in the Hyper-V host.  You can disable VMQs in the properties of the physical adapters in Control Panel within its Properties >> Configure >> Advanced tab. If you wish to use VMQs in the host, ensure they are only enabled if the NIC hardware is capable of properly supporting it.

Additional information:

https://community.spiceworks.com/how_to/124202-how-to-disable-vmq-with-powershell

Need more help?

Get in touch with our friendly help desk who will be happy to assist you, support@foldr.io