While Microsoft continue to play catch up to VMware in the virtualisation market they seem to be lagging behind quite significantly in terms of the quality of their product. Judging by various well respected forums and my own experience of installation & rollout into a production enviroment there are quite a few problems of which i'll list out the 4 prevalant ones :
1. Slow Network Response.
This seems to be the number one issue with Hyper V, it can be resolve 90% of the time by disabling the tcpv4 Large offload stack on the Host NIC and the Virtual Server NIC, There does seem to be hardware issues in the remaining 10% of cases which can be resolved generally by changing the Physical NIC to one confirmed as supported by Hyper V
2. Long installation time.
Apparantly when Microsoft changed/upgraded from Virtual Server to Hyper V there was some legacy issues brought accross without resolution one of these legacy issues was the slowness of emulation of drivers during install which can lead to a very laborious install.
3. Network redundancy.
You are unable to link more than one NIC to a virtual switch
4. The Host operating system is also windows.
This doesnt sound like too much of an issue but it does turn out to be, It means that every time i have to run windows updates on the host system i have to shut down the Virtual servers. If an update fails or corrupts the Host operating system then i lose the virtual servers and lastly the host is susceptible to Virus's and security loopholes.
Most of the problems with Hyper V Microsoft say they are working on fixes for them but for my money i'm sticking with VMware purely and simply because it makes my live easier...
