Re: partition table type
This is mostly incorrect. The firmware type and the partition table type are largely independent of each other. It's possible to boot a BIOS-based computer using a GPT disk; you do not need EFI (or its more recent variant, UEFI) to boot from a GPT disk. You do need boot loader and OS support for GPT, though. The GRUB 2 that Ubuntu uses by default supports GPT booting, although you may need to create a BIOS Boot Partition to get it to work reliably. Linux, including Ubuntu, also supports GPT booting. Windows does not support booting from a GPT disk on a BIOS computer, but that's a Windows limitation, not a BIOS limitation.
Originally Posted by mcduck
There is a big caveat to all, this, though, and that is that some BIOSes have bugs that cause them to flake out when attempting to boot the computer from GPT disks. I've written up details here. There are workarounds to some (perhaps all) such problems. Some Intel boards, in particular, have such bugs. With them, there are at least two possible workarounds or fixes:
- You can add the "boot" (aka the "active") flag to the protective MBR's type-0xEE partition. This is easily done with Linux's fdisk -- just use the "a" option and then save the changes with "w". Note that you must use fdisk, not parted or GParted, to do this; parted and GParted won't do what's needed in this situation.
- With at least some Intel boards, you can use UEFI booting rather than BIOS booting. There's a setting for this on the boot options page in the setup utility. Using this feature will require changing the boot loader and creating an EFI System Partition (ESP), if one doesn't already exist. If Ubuntu isn't yet installed, you'll have to be sure to boot the installer in UEFI mode to get the right boot loader to install.
One more comment: Although most existing PCs are BIOS-based, many (perhaps most) of the motherboards introduced this year, including most or all that use Intel's Sandy Bridge CPUs, are UEFI-based. Some manufacturers try to downplay this change by using firmware interfaces that look just like old BIOS interfaces, by relying on BIOS compatibility modes for booting, and even by referring to the firmware as a "BIOS," but they are UEFI-based nonetheless.
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