grub2

[Chris Murphy]

On May 4, 2014, at 4:33 PM, Patrick Dupre <pdupre at gmx.com> wrote:

> Hello,
> 
> After the installation of a new kernel (typically during an update).
> There is a change of the file /boot/grub2/grub.cfg.
> 
> However, the new menuentry created is not correct.
> The new one includes
> linux   /vmlinuz-3.14.2-200.fc20.x86_64 root=/dev/mapper/VolGrpSys_DK1-root
> which wrong.
> I can change it manually.
> 
> I cannot guess where the information is found!
> the 
> set root='lvm/VolGrpSys_DK1-root'
> 
> is correct

The first one looks correct, the second one doesn't. Can you either post the entire grub.cfg, or you can also edit an older entry and check what root= it uses. For any rootfs on LVM, I expect root=/dev/mapper/VG-LV. When updating the kernel, it calls grubby, which should just create a new entry based on a previous entry only updating the name of the kernel and initramfs accordingly. I haven't seen it change the root entry.

The other thing you can do is create a new grub.cfg from scratch by using 

grub2-mkconfig -o /boot/grub2/grub.cfg

This is the same command the installer used when Fedora was installed.

Chris Murphy