Questions[uefi](server)

As discussed elsewhere, Windows Server 2008/R2 will automatically use the EFI boot loader when installed on EFI systems, and will also automatically use the GPT partitioning scheme on such systems. And you can't do anything at all about this (other than force the system to switch to BIOS, if this is supported).

But, as documented here, VMware Converter is not going to convert GPT disks. Which is actually quite suprising, when considering that it supports EFI systems and they in turn use GPT disks... but that's it.

So, how to perform a P2V conversion on EFI/GPT Windows servers?

RFC 4578 defines various machine architectures for PXE as follows:

Type   Architecture Name
----   -----------------
  0    Intel x86PC
  1    NEC/PC98
  2    EFI Itanium
  3    DEC Alpha
  4    Arc x86
  5    Intel Lean Client
  6    EFI IA32
  7    EFI BC
  8    EFI Xscale
  9    EFI x86-64

I've tested out two IBM machines (HS22 blade, x3550M3) and they both do EFI PXE boot using the 'EFI BC' architecture.

What does it stand for? When is it used? Why is IBM using it instead of 'EFI x86-64'?

I have an existing PXE syslinux environment and I'd like to set up a similar EFI-based netboot environment.

I'm a big fan of the various menus as seen in the screenshot below and I'd like to find something equivalent.

Ideal features would be:

• Menus
• Sub-menus
• Linux kernel/initrd TFTP load (naturally)
• Arbitrary EFI application load
• Fallthrough to next boot option

What piece of software meets these needs?

We have UEFI servers and have come across a situation where we need to force Windows Server 2008 to boot via the legacy BIOS method instead of through UEFI.

Is there a way to tell Windows Server 2008 (either during install or post-install) to ignore the fact that it's installing onto an EFI machine and instead install and use the legacy BIOS bootloader?

I've tried a few suggestions which didn't help:

• Format disks as MBR partitions before installing Windows

  Nope, Windows refuses to install:

• Install Windows, migrate the partition to an MBR disk, repair system

  Nope, the system repair console refuses to load. It complains that it doesn't recognize the version of Windows I'm attempting to repair.

• Disable UEFI

  If I could disable UEFI and make the system legacy-only, I would have. However, the particular systems I'm using (IBM HS22, x3690X5) are UEFI-only with legacy support. You can't just disable UEFI on them. That would require a complete BIOS implementation.

The Solution!

As JdeBP points out, the sole method Windows uses to determine whether to use the EFI/GPT or BIOS/MBR bootloader is the method which was used to boot the install CD.

Combining this with Weaver's suggestion to craft a .iso image without the 0xEF boot catalog entry (far easier to do by hex-editing rather than remastering the image, by the way) leads us to a nice, concise answer:

Force the install media to boot via BIOS, not via UEFI as this is the only differentiator Windows Installer uses to determine which boot scheme to use.

I have a pair of IBM System x3620 servers. These servers do fine once they finally reach the point where the operating system takes over, but it takes them forever to get past the new-fangled UEFI boot system... a good five minutes or so; maybe longer. I haven't timed it, but it's the kind of thing where you go get a cup of coffee while you wait and it's still going when you come back.

Normally the only time I shut these down is for a monthly maintenance cycle (usually just windows updates). It's built-in maintenance time, and so the extra 5 minutes don't count against our SLAs and aren't a big deal. However, in the case where I might have an outage I'd sure like to get those 5 minutes back. Is there anything I can do to tell them to just go ahead and boot already? I've already disabled everything I can find to disable as far as extra boot options go.