When dealing with Windows Server 2008 R2 installations on EFI systems, we encounter an architectural constraint where the OS automatically:

• Deploys the EFI boot loader
• Enforces GPT disk partitioning
• Prevents conversion to MBR without complete reinstallation

VMware Converter's current 6.x-7.x versions exhibit paradoxical behavior:

if (disk.IsGPT) {
    throw new UnsupportedDiskFormatException();
} else if (system.IsEFI) {
    // Proceeds with conversion but may fail at boot
}

The fundamental incompatibility stems from:

1. Lack of GPT-to-MBR translation layer
2. Incomplete UEFI firmware emulation in generated VMX files
3. Boot sector reconstruction challenges

Method 1: Disk2VHD with Manual VM Creation

# PowerShell disk capture
disk2vhd.exe \\physical-server\c$ c:\conversion\server2008r2.vhdx

Then create VM with these specifications:

.vmx configuration:
firmware = "efi"
disk.EnableUUID = "TRUE"
bios.forceSetupOnce = "TRUE"

Method 2: Hybrid Conversion Approach

1. Use dd/ddrescue for raw disk capture
2. Convert GPT to MBR using gdisk:

gdisk /dev/sdX
x # Expert menu
z # Zap GPT header
n # New MBR

For converted VMs that fail to boot:

# From Windows Recovery Environment
bootrec /fixmbr
bootrec /fixboot
bcdboot C:\Windows /s S: /f UEFI

Critical registry fix for disk signatures:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices]
"\\DosDevices\\C:"=hex:3c,1d,3d,3e

Tool	GPT Support	EFI Awareness
VMware Converter	No	Partial
StarWind V2V	Yes	Full
Disk2VHD	Yes	Full

---

When attempting to perform a Physical-to-Virtual (P2V) conversion of Windows Server 2008 R2 systems with EFI firmware and GPT disk partitioning, administrators face a fundamental limitation: VMware Converter (both standalone and vCenter-integrated versions) doesn't support GPT disk conversion despite supporting EFI systems.

Windows Server 2008/R2 automatically uses:

- EFI boot loader when installed on EFI systems
- GPT partitioning scheme on disks >2TB or EFI systems

The core issue stems from VMware Converter's architecture which was designed primarily for MBR disks in early versions and never fully updated for GPT support.

Option 1: Disk Conversion with gpt2mbr

1. Boot from Windows installation media
2. Launch Command Prompt (Shift+F10)
3. Run diskpart:
   > list disk
   > select disk X
   > clean
   > convert mbr
   > create partition primary
   > format quick fs=ntfs
   > active

Warning: This requires complete reinstallation as it destroys existing partitions.

Option 2: Manual VMDK Creation

# Using qemu-img for raw conversion
qemu-img convert -f raw -O vmdk /dev/sda windows2008r2.vmdk

# Create VM with matching specs:
vmware-vdiskmanager -c -s 50GB -a lsilogic -t 0 mydisk.vmdk

Requires additional configuration of VMX files for EFI support:

firmware = "efi"
efi.legacyBoot = "FALSE"

For enterprise environments, consider:

• StarWind V2V Converter (supports GPT disks)
• Disk2vhd with subsequent VHD to VMDK conversion
• Physical ESXi host with raw device mapping

Example Disk2vhd command:

disk2vhd.exe \\server\c$ c:\conversion\server2008r2.vhdx

After successful conversion:

1. Install VMware Tools
2. Verify bootloader integrity (bcdedit /enum all)
3. Check disk alignment (wmic partition get BlockSize,StartingOffset)
4. Update storage drivers (esxcli software vib install)

For批量 processing:

# PowerShell conversion wrapper
$servers = Get-Content .\serverlist.txt
foreach ($server in $servers) {
    Invoke-Command -ComputerName $server -ScriptBlock {
        disk2vhd C: D:\$env:COMPUTERNAME.vhdx
    }
    Start-Sleep -Seconds 300
    Convert-VHD -Path "D:\$server.vhdx" -DestinationPath "\\san\vmware\$server.vmdk" -VHDType Dynamic
}