25 ms·

So UEFI requires a GPT to be present, doesn't it? Otherwise what's the objective difference between an invalid GPT and no GPT?

• creshal 8y ago
  A valid GPT header either at the beginning or end of the disk. Due to how the GPT header is structured, the secondary starts with the partition table and ends with the header signature in the last 8 bytes of the disk. So unlike with MBR disks, you can't just nuke the first few sectors and call it a day, you have to wipe the whole disk (or use a GPT-aware tool like wipefs).
  • vbezhenar 8y ago
    Can I wipe first few sectors and last few sectors?
    • rwmj 8y ago
      Use wipefs.
    • mjevans 8y ago
      To make it look empty, yes. It's much easier to use a tool like sgdisk sgdisk -Z sgdisk --zap-all (note the capital Z)
• Filligree 8y ago
  Going by GP, if neither the primary nor backup GPTs are valid then nothing should happen. I would still recommend having a GPT, though. There's nothing useful to be gained by avoiding it, and we've just seen what sort of failure modes can come up.
• wtallis 8y ago
  No GPT is required. Problems only happen when you have partial or conflicting partition table information. If you want to not use GPT on a disk, you need to make sure to delete both copies.