Boot from GPT HDD without UEFI BIOS?
 

Is it possible to boot from a GPT-partitioned HDD with non-UEFI BIOS and GRUB 2 (1.xx)?

If so, are there any size constraints? Are there any good references explaining how the components fit together and how to use them?

I am advised it is not possible. Searching the 'net has not found any pages suggesting it is possible. But I once set up that configuration and it worked. I accidentally selected GPT while interactively installing Debian 6 Squeeze on a Supermicro X7SPA-HF-D525. That is a 2011 motherboard with an Atom processor so surely (?) does not have (U)EFI BIOS. The HDD was a 2 TB model.

Certainly.
Fedora has for a while defaulted to gpt if you choose to use the entire disk - and RHEL/CentOS by the looks of it from the install guide (only if disk is greater than 2T uness you force the issue).
I'd be willing to bet either Gentoo or Arch wiki will have some relevant doco - I've seen some in my travels.

Thanks syg00 :)

Will look in the Gentoo and Arch WIKI for knowledge and post findings. They will initially be for ubuntu 12.04 32-bit :(

The Arch WIKI (https://wiki.archlinux.org/index.php...c_instructions) was very helpful.

Following its advice I used cgdisk to create a 1007 KiB type ef02 "BIOS Boot Partition" at the start of a re-initialised 3 TB HDD.

Then installed Ubuntu 12.04 32-bit. It didn't boot so, following a suggestion on the linked Arch WIKI page, I used cfdisk to mark the only partition listed (FS Type: GPT) as bootable. That may not have been necessary if I had used the installer to create the "BIOS Boot Partition".

Having proved that the BIOS+GPT+Ubuntu-12.04-32-bit combination is possible, the next step is to upgrade our in-house server with a pair of 3 TB HDDs. Any useful information gained will be posted here.

Upgrading our in-house server with a pair of 3 TB HDDs was straightforward.

After using cgdisk to create a 1007 KiB type ef02 "BIOS Boot Partition" at the start of both new 3 TB HDDs we ran grub-install /dev/sd<whatever> on both. The booting from GPT HDD without non-UEFI BIOS simply worked.