On Mon, 2025-08-18 at 15:31 -0400, Felix Miata wrote: > David Wright composed on 2025-08-18 11:13 (UTC-0700): > > > On Mon 18 Aug 2025 at 00:31:13 (-0700), Van Snyder wrote: > > > > Is this an unavoidable intrinsic problem with UEFI, or is it a > > > twelve- > > > year-old bug in grub-install or grub-mkconfig — or whatever the > > > Debian > > > installer uses? > > > I don't think you've posted your new layout, so I'm only guessing. > > > It's not the size of the disk (<2TB), but you did have the EFI in a > > logical partition, not a primary one. AFAIK that's not necessarily > > out of specification, but it might not be supported by your > > particular machine's firmware. > > I'm coming up short finding the authority on this, but I'm pretty > sure there is no > such thing as booting from an ESP that isn't on a GPT-partitioned > disk, with > correct type assigned. I think the ESP type is technically at least a > 4byte value > not supported by MBR disks, which are limited to 2byte types. The ESP > also has a > unique UUID type c12a7328-f81f-11d2-ba4b-00a0c93ec93b that has no > place in an MBR > table.
The boot record is MBR not GPT, but with the EFI partition primary and at a low enough address, the grub installation worked. As far as I can tell, one cannot change the boot record to GPT without wiping out the partition table, which would require me to take a backup of the 1 TB drive. > I missed Disklabel type: dos in the 2025-08-17 15:03 -0700 post, > likely by seeing > the ESP on NVME. :p
