Disabling VMQ on Hyper-V Parent Partition with 1 Gbit Broadcom NICs - Any Major Concerns?
Posted on 2014-08-04
I have a client running a Hyper-V 2008 R2 SP1 environment with around 15 VM's including (Exchange 2010, Lync 2010, and SQL Server 2008 R2) running on a single Dell R720xd server that is not currently clustered. Please note that I inherited this environment and had no say in how it was set up, so I am not asking about HA, shared storage etc. as they are currently not in the client's budget.
However, I did notice that copying large files (e.g. a 30 GB database file) between two VM's running on this same Hyper-V parent partition did so at speeds of around 7 MBytes per second. This seems very slow to me, and upon doing research about slow network speeds between Hyper-V VM's running on top of Broadcom NICs, I discovered that it can be beneficial to disable VMQs on the Broadcom NICs (which is enabled by default). I am not one who likes to just disable default settings without a logical reason, and I realize that VMQs have some major performance benefits when implemented correctly. However, my server has only 1 Gbit NICs in it, and the network traffic to even the most used VM's is very light in general.
My questions are as follows:
1. Do I lose anything major by disabling this VMQ feature on all Broadcom NICs in the parent partition running Hyper-V 2008 R2 at 1 Gbit speeds? My client has a mix of Server 2003, 2003 R2, and Server 2008 R2 servers running on this Hyper-V server, some of which cannot even make user of VMQs if I am not mistaken. And currently, the parent partition is not setup via the registry to use VMQs for either 10 GBit or 1 GBit NICs.
2. When I disable this setting on the NICs of the parent partition, will I need to reboot the underlying Hyper-V server for the change to take effect? This is critical for me since the client's entire infrastructure currently must be shut down for the parent partition to be rebooted (again, in my defense- I inherited this setup!! ;-)
Thanks in advance for any guidance you may be able to provide.