Hello, I am currently building LFS 7.5-systemd using a virtual machine mounted over CentOS 7 with x86_64 architecture.
I am already working in chapter 8 and so far every step in this chapter went flawlessly until I had to install grub with "grub-install /dev/sda", in which I get the error Path `/boot/grub' is not readable by GRUB on boot. Installation is impossible.
Now, I am currently working my LFS in /dev/sdb1 and have my swap in /dev/sdb5, building the whole LFS system in another hard drive in ext4. I am not sure if because of this I am supposed to change the command to "grub-install /dev/sdb" or "grub-install /dev/sdb1" but it's not working in any case.

I've heard there is an issue with installing the grub in ext4 systems, is there a way to use a third hard drive to use as boot?

It depends on which partition you want to install the grub, and you must have the mount point.

From your post I guess you want to install grub at hard disk /dev/sda, but you may also specify the directory where you want to write the files for grub.
Let us say, you want to write the grub files at /dev/sda1, then you can first mount it
And then install grub by

1 members found this post helpful.

I have resolved doing that same thing, thank you!