I ran into the same bug too, booting 20.04.4 from a 4TiB partition partition on a 4TiB disk. No RAID or LVM, plain 4TB ext4 partition.
I have grub installed in a bios-grub partition, sectors 34-2047. The problem seems to be that by default, Grub uses BIOS drivers to load files from the target partition. This is tersely documented in the Grub 2.06 documentation, in the "nativedisk" command paragraph. When using native grub drivers (ahci in my case), everything works. Ditto after running the nativedisk command from the Grub rescue console. I solved the problem by re-running a grub-install with parameter --disk-module=ahci The problem with that approach is that any further grub-install without those parms (like an Ubuntu software update might decide to do) will zap the native driver from the Grub partition, and break the boot again. grub-install should never generate a broken boot when it can avoid it: Ideally, when grub detects that at least one of its target partitions crosses the 2TiB boundary, it should give a warning and do a grub-install with the --disk-module=MODULE parameter. 4TB SSD disk prices dropping fast (below 350€ these days). This problem might increasingly show up... -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1918948 Title: Issue in Extended Disk Data retrieval (biosdisk: int 13h/service 48h) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1918948/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
