I have just come to do a P2V of a server setup with a GPT partition table and discovered that the P2V tool on 2008 R2 VMM doesn't support conversion of GPT disks.
The MS article suggests two ways around this;
1) Use Disk2Vhd.exe tool to create the VHD files, create a new VM, link in the VHD files, then boot to the 2008 R2 DVD to repair it.
I tried this and not surpisingly it wouldn't boot straight off and it also wouldn't let me use the repair option when booting from the Virtual DVD (something about wrong version of Windows even though it was the correct version).
2) Convert partition table type from GPT to MBR (which wipes all data), then restore the "data" from a backup. It doesn't say anything about system boot partitions.
The problem with this is whether a BMR backup can be used to restore the server *after* changing the partition table type from GPT to MBR.
If the BMR doesn't work, I could be left with no working version of the server (either physical or virtual).
Has anyone encounted this problem before? Or any advice?
I did quite bit of research, and it appears that both VMware and Hyper-V have the same issue with virtualizing servers with GPT partitions, basically neither support VMs with GPT paritions (consequently P2V of existing servers with GPT partitions will fail).
The reason is that both virtualization environments emulate the older style BIOS in the VM but not the newer UEFI BIOS/architecture (found on newer servers) on which GPT partitions depend.
The other problem is that apparently the Windows installation is tied closely to the partition type (e.g drivers etc., configuration), so it's no simple matter of tweaking the partition type in the VHD, as Windows will get confused and won't boot.
Someone has produced a free tool which is supposed to allow you get around this (it does a disk2VHD, converts the partition to MBR then attempts make the appropriate changes to the Windows boot/driver to fix the boot problem). However, it's a third party tool and there is no guarantee it will always work. I didn't have time to try it
My advice, if you are setting up a new server with 2008 R2 and there is any possibility of the need to convert this to a VM at a future date, then choose MBR rather than GPT. Apparently 2008 R2 defaults to GPT if it detects a UEFI BIOS, so you need to actively change it from GPT to MBR during installation. I don't know what 2012 defaults to.
I am surprised this issue hasn't come up more often, but the UEFI BIOS is a fairly recent development and most people are P2V-ing existing (older) servers.
Last edited by Bruce123; 23rd July 2012 at 05:44 PM.