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Location of grub.conf etc. with UEFI boot (CentOS 6)

Hi,

What's the proper/normal way of setting up GRUB for a CentOS 6
installation that boots using UEFI? I've recently set up such a system,
but for technical reasons I mentioned in an earlier post, I booted in
"legacy" mode during installation, which meant I didn't get the correct
UEFI boot configuration, and had to set it up subsequently "by hand".
I've managed to get the system to start up, but I had to place grub.conf
under "/EFI/redhat/" on the EFI partition; without it, the system only
boots into the grub shell. Is this normal, or is GRUB supposed to be
able to find grub.conf under /boot? If not, how are updates on kernel
upgrade etc. supposed to get done? Do I need a symlink from
/boot/grub/grub.conf to the EFI parition? And will grub-install help
with some of this? I haven't dared to try it, as I'm afraid it may break
everything because it assumes an "MBR" configuration, or something.

Also, how is /boot supposed to be set up anyway? Will it still normally
be configured as a separate partition?

Yeah, I know, I could re-install in UEFI mode (as I think I know how
now), but I'm hoping you will save me from the effort. I also have a
workable system anyhow, but kernel upgrades could be an issue, and it's
nice to know the "right" way of setting up.

Thanks,

 -Toralf

Comments

Re: Location of grub.conf etc. with UEFI boot (CentOS 6

By Jonathan Billings at 10/11/2017 - 07:46

On Oct 11, 2017, at 8:38 AM, Toralf Lund <toralf. ... at pgs dot com> wrote:

Yes, UEFI boots with a UEFI grub executable, and it looks for a grub.cfg in the /EFI/redhat/ directory, next to the grub executable.

Typically, you have the UEFI partition mounted as /boot/efi, and grub knows to find the grub.cfg in the subdirectory there. The kernel package runs ‘grubby’ which knows how to update grub if there’s an EFI partition mounted.

My experiences have been only with CentOS7 and RHEL7 with UEFI, which uses grub2. However, the RHEL6 documentation confirms these paths: <a href="https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Installation_Guide/s2-grub-whatis-booting-uefi.html" title="https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Installation_Guide/s2-grub-whatis-booting-uefi.html">https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6...</a>