Written by Thomas Koetzing at Monday, 16 August 2010 | Article editor: Carl Webster
Recently I had the task to convert physical Servers to virtual XenServer (P2V) instances and with Windows Server 2000/NT as the operating system. All Servers where from HP and old Hardware like ProLiant 5500, DL 580G0 with SCSI hard drives with 4GB and 8GB max capacity.
Physical to Virtual (P2V) of Windows Server 2000 SP4 and NT Task was to virtualize a bunch of existing MetaFrame XP Servers on Windows Server 2000 SP4 and Windows NT to XenServer 5.6 running on HP blades BL460c G6 with 48GB RAM and 126GB SAS hard drives. The migration had to be done while keeping the farm up and running for users. Virtualization was one step but at the same time I also wanted to consolidate Servers or even eliminate unneeded Servers. As a matter of fact, some Servers were running for years but no one was using the Servers! In total, three Racks of Servers migrating into three XenServer hosts and one Rack of Servers were not needed!
Citrix XenConvert to virtualize the Server hardware Most of the servers had an 8GB system drive and no need to say that they were also running out of disk space. With XenConvert 2.1 you can easily extend the destination device to higher capacity, like 14GB.
Still chose a system drive not so big, because the drive can be simply expanded afterwards. To expand the drive size later, shut down the machine and expand the size of the hard drive in XenCenter. Now what you need is a VISTA/Win7 recovery CD (yes there are more ways to do it) to boot the VM from. You get to the recovery part where you pick the command prompt. With the "diskpart" command (list volume, select volume, extend) you can simply extend the boot drive (or any other).
Back to XenConvert, make sure you run it on the server console, which means with Server 2000 use a remote inside board (if available) or something like VNC. You might get some not helpful error messages if you are not on the console. For the working space you could use a network share but make sure you have a good and stable connection.
What happened is that XenConvert creates additional drives that you can see in the disk manager and it will copy files to the new drive(s). In the working space XenConvert creates a VHD, PVP and OVF file. With those files you can basically use it with any Hypervisor (in theory) and Citrix Provisioning Services.
Adjust converted Machine Sometimes the VM parameters are not the same or show additional NICs that you might not need anymore. Simply change all settings of the VM so it fits your needs and make sure you set the XenApp performance for XenApp Server.
Cleanup of the virtual machines After XenConvert has success in converting the machine to XenServer, you need to clean up the machine. What does that mean? Most important, you might have some problems with the HAL ending up with the VM pegging the CPU to 100% when even within the machine it doesn’t show that. Next you might have some service running from the hardware vendor that you need to get rid of and also old devices like the Network card. Actually the network card can give you a hard time and people just try to find the right thing in the registry but there is a much easier way.
First, the HAL fix for 100% CPU on the host. There is a bug with Windows XP and Server 2000 that could be the reason why the host shows 100% CPU. A simple registry value and reboot will fix the problem, read the following article KB835730 for more details.
Next, something that might not be so obvious is the MPS Multiprocessor Windows kernel. If you have an APCI Multiprocessor you are fine on Hypervisor but not with MPS. Even if your VM has two or more virtual CPU's you still will get 100% CPU on the host. There is only one way to fix it and is to change the kernel to MPS Uniprocessor, yes just one CPU. This is done by the device manager as described in the following Microsoft article KB237556.
You cannot change MPS to APCI in any way and if you do, the next boot will be a blue screen with an inaccessible boot device error. For more details read the article KB309283
Remove old devices and services You should make a snapshot of the VM if you are not sure what you are doing. Uninstall the Hardware vendor software and services. This is important especially for the network card and you can do this in a nice way with the device manager. Follow knowledge base article KB315539 to show hidden and non-present devices.
In addition you might need to remove the service(s) from the registry by yourself.
Finalizing After the cleanup of the VM you should install the XenServer Tools and reboot the VM. Now after the reboot it's time to set the network parameters in your VM. If you have P2Ved a XenApp Server make sure you run the dsmaint command to recreate the LHC and the RADE (streaming) with "DSMAINT RecreateLHC" and "DSMAINT RecreateRADE". Reboot the VM again and afterwards check the eventlog for services that could not start and fix those issues.
The human factor Implementing and installing servers is what people love to do but when it comes to removing or consolidating servers people seem to hide or go looking for excuses. First of all it's important to collect data: what's the need for the server, who is responsible for it, is the server still needed? By just asking questions I could simply turn off servers! Next was more difficult when asking can we move databases, can we share the server or service? Problem here is that people are leaking knowledge and it's easier to keep things running the way they are. What will you hear: "Never change a running system" but you should when they're ages old! People say one year in IT is like seven years in a human life, so windows Server 2000 is now 77 years old and should be retired for a long time. By doing so I was able to turn off another couple of servers after migrating and consolidating. It's a human factor that needs to be overcome in order to reduce the amount of servers and their power consumption.
Summary The procedure of P2V was quite painless once I found out all the little things that needed to be done. The move was done with production servers (XenApp Farms) and without the user knowing about it. Talk with the whole IT department and by overcoming fears of migrating or consolidating you could turn off quite a few servers after evaluating their purposes and redundancy. The amount of power consumption and therefore money that has been saved every month is huge because it's not just the reduced server hardware but also air-conditioning is now running on a lower level. btw. who said the air-conditioning has to run below 68F? As a side effect of the P2V process the environment has been simplified and optimized.
Do you think your environment has the same potential of power saving? Let me know!
Written by Guest on 2011-01-19 20:59:59Have you tried converting using Xenconvert 2.3. It appears it requires DHCP to be running to work. Is there and advantage of using Xenconvert 2.3 over Xenconvert 2.1.1