Wednesday, January 14, 2009

Poor network performance on Microsoft Hyper-V

I recently installed a Windows Server 2008 with Hyper-V to host my Virtual Machines. As overall performance seemed to be better than on Virtual Server 2005, I ran into very poor performance when copying files between the Guest and Host using a file share.

I tried several solutions I’ve found on the net, but in the end, I found that one should NOT use the ‘Legacy Network Adapter’ in Hyper-V but use the ‘Network Adapter’ when adding a network card to the VM.

When copying a 4GB (iso) from the VM to a (shared) USB drive attached to the Server, the speed went from barely 2MB/s to a reasonable 17MB/s.