Re: GRUB2 not able to read ext4/xfs file systems on 8 TB drive

[Pascal Hambourg]

Le 23/04/2020 à 03:46, Niklas Hambüchen a écrit :
> You are right, I have tried it now without `pata` and it still works.

Also part_msdos should not be needed since the partition scheme is GPT.

> I tried this with SuperGrub2Disk, but oddly `ls (hd0)` and `ls (hd0,gpt2)` show 
> the full sizes (8 TB).

Reporting the correct size does not imply that the firmware driver can 
address all of it.

> > However couldn't you just use a separate RAID array based on small partitions 
> > located at the beginning of the drives for /boot ?
>
> I think I could -- but would it be preferable?

It would not require to build a custom core image. Some distributions 
such as Ubuntu that you mentioned reinstall the core image when grub 
packages are updated, and I am not sure that the package can 
automatically handle extra custom grub-install parameters.

Also, GRUB would not even need to use the LVM driver in order to load 
the kernel and the initramfs, making it simpler and safer. If anything 
goes wrong with the LVM, GRUB won't even be able to boot the kernel. 
With a separate /boot, GRUB would at least boot the kernel, making the 
rescue initramfs shell available.

> It seems that with `nativedisk` I can achieve a correct boot and be more 
> independent of bugs in the firmware, which looks like a strong argument to me.

Native disk drivers are much less used than firmware disk drivers, so 
they are also probably less tested. Then may contain bugs too. Also, 
when I tested (a long time ago), native disk drivers were much slower 
that firmware disk drivers.