Poor network bandwith idn Win2012R2

[halozan]

We have ESXi 6.0 and Windows Server 2012R2 machines. They are having latest VMWare Tools installed and are usin VMXNET3 network adapter.

One of machines is hosting MS AX Dynamics AOs server.

When we issue axbuild command to compile AOS, the network preformace is very slow (arround 2-5 Mbs). During build the ASO server is establishind a lto of connections to MS SQL Server. The total compile time is 13 hours.

After we have installe Wireshark (v2.01) inf WinPcap driver, the network performacne increase to avverage 120 Mbs, sometimes to 400Mbs. The overall compile time was only 21 minutes.

We don't know what is WinPCAp driver doing on TCP stack, but it increses performacne. Our goal is to runn server without wrieshark installed. Are there any special settings in VMXNET3 driver?

regards

[MKguy]

This is a known issue with vmxnet3 and Windows 2012 on ESXi 6.0 with vHW 11. It's been resolved in ESXi 6.0 U2 that was released a while ago.

If you can't upgrade then the best workaround currently is to disable RSC offloading in the GuestOS, e.g. with this command:

netsh int tcp set global rsc=disabled

See this KB article for details:

VMware KB: After upgrading a virtual machine to hardware version 11 network dependent workloads expe...

[Shoomy]

Change to E1000E adapter and see if the performance increases.

There is a bug in VMXNET3 which causes performance issues with SQL. There are several solution but for us none worked. Changing to E1000E solved our problems with bad performance in combination with DB's

[halozan]

Thanks, this solution has worked for me.

Regards,