On Wed, 18 Apr 2018 00:04:53 +0200
André Verwijs
question: does a PC BIOS/disk controller has to support GPT partitions?
Yes and no. The main reason and justification for GPT is disks of >2 TB, which is the maximum for MBR partitioning. You can use GPT on smaller disks, of course, and Intel Macs default to GPT. There's no real need for GPT on disks of <2 TB, but it works, and I have seen people advocating it for disks in the 500+ GB range. (GPT is easier to understand as it eliminates the primary/secondary partition distinction and the existence of "extended partitions".) The legacy BIOS does not contain support for GPT*, but GPT contains an emulated MBR so that a legacy BIOS should be able to read a GPT disk and possibly even boot from it if you're lucky. :-) UEFI firmware natively supports and expects GPT. It also expects a special "EFI system partition" on GPT disks in which to store data about bootable OSes: https://en.wikipedia.org/wiki/EFI_system_partition Again, *in theory*, if you have UEFI, you *must* have an EFI system partition for the disk to be bootable. In principle, for GRUB to boot Linux from a GPT disk in an MBR machine, the disk needs a special "GRUB BIOS boot partition": https://en.wikipedia.org/wiki/BIOS_boot_partition Apparently, this previously worked for you, but in theory, it should *not* have worked, and you should not rely on it working in future. * In principle. There are probably exceptions. These are PCs we are discussing, after all. -- Liam Proven - Technical Writer, SUSE Linux s.r.o. Corso II, Křižíkova 148/34, 186-00 Praha 8 - Karlín, Czechia Email: lproven@suse.com - Office telephone: +420 284 241 084 -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org