How not to virtualize a server

I had a less than ideal experience with Hyper-V the other day. We finally got a server that we had borrowed to a customer back and it was time to install it for ourselves. Windows server 2008, here we come.

Since i think it’s a wrong-doing of nearly criminal proportions to have a server to run just one instance of an operating system these days, it was only natural to me to run a hypervisor layer on the server and stack servers on that hypervisor layer. And since Windows server 2008 Enterprise comes with Hyper-V and licenses to run four instances of itself on it [0] that seemed the logical path. After all we’re a Microsoft shop, so screw VMware and screw open source solutions like the Xen hypervisor.

Installing Windows Server 2008 was nearly painless. Since the hardware i was working on is a HP pizza box, the correct working order is to boot the box with HP’s SmartStart package. This tool helps to configure the RAID, set up the partitions, install Windows Server and all the platform specific drivers (and keep them up to date!). Sadly, the version of SmartStart i had would not support Windows Server 2008, but at least i got the RAID configured with it and after that i could boot with the Windows Server installation disc while i was downloading a newer SmartStart. After Windows Server 2008 was installed, i was able to “patch” the system with SmartStart version eight point something. This added, among other things, the HP network interface teaming which adds redundancy and throughput to the network connectivity.

Adding Hyper-V support for Windows Server was also nearly painless. From the server administration console, i just added the Hyper-V Role and with the obligatory system reboot, i changed the BIOS settings to allow “Intel Virtualization technology”.

But from there, it was all downhill.

The Hyper-V console dryly informed me that the virtual machine management bits were unable to start (the two other components for Hyper-V started without a hitch). And to make things worse, the computer suddenly refused all incoming connections. I checked the firewall, but nothing there seemed to suggest that the system now was in some kind of hardened mode. Outgoing connections were okay. The firewall explicitly allowed remote desktop connections, but nothing would come in. Not even a ping.

Today i removed the Hyper-V role and the server came back to normal. It is possible that the HP network interface teaming bit is incompatible with Hyper-V, as you’re supposed to leave one NIC reserved for the host and assign the remaining NIC(s) for the virtualized machines but even when i dissolved the teamed network interface cards, Hyper-V just wouldn’t budge.

I suppose we’re either going to have to wait for a HP/Hyper-V update. If it really is true that you can install true hypervisor support on an already deployed Windows Server 2008 platform, then we can wait. Otherwise, it just feels like a waste. Or time to give Xen another look…

[0] i know i’m starting to sound recursive here; i was intending to run four instances of Windows Server 2008 on the Hyper-V built into the base installation of Windows Server 2008