Repair boot to Windows from GRUB after disabling intel Rapid Storage Tech (RST) / VMD RAID in BIOS

I disabled intel Rapid Storage Tech (RST) / VMD RAID in BIOS due to poor battery life during sleep in Fedora with this enabled. I have tried both enabling and disabling this setting and battery life during sleep seems much better with this BIOS option disabled.

Interestingly, making this change appears to have no impact on Fedora. Fedora purrs along fine with this setting enabled or disabled.

However, switching this setting from ‘off’ to ‘on’ (or from ‘on’ to ‘off’) will completely break Windows. The boot partition becomes inaccessible.

My Dell XPS 15 9530 laptop has two drives; one has Windows 11 on it and the other has Fedora on it. Since Windows was already installed on one of the drives when I installed Fedora, Fedora automatically configured grub to allow me to boot to the Windows 11 drive from the grub menu on boot.

When I turned the RST / VMD RAID setting in BIOS from ‘on’ to ‘off’ I needed to reinstall Windows on the Windows drive because it would not boot. Fedora continued to work fine, however now I get an error when I try to boot Windows from the Fedora grub menu.

Here is my grub file:


wiking@fedora:~$ cat /etc/default/grub
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="gfxterm"
GRUB_GFXMODE=1280x720
GRUB_CMDLINE_LINUX="rd.luks.uuid=luks-82adf451-f027-4115-9dd7-46575fb4a044 rhgb quiet"
GRUB_DISABLE_RECOVERY="true"
GRUB_ENABLE_BLSCFG=true

Okay I figured it out. All I needed to do was reinstall grub:

sudo rm /boot/efi/EFI/fedora/grub.cfg
sudo rm /boot/grub2/grub.cfg
sudo dnf reinstall shim-* grub2-efi-* grub2-common

When I did this, it automatically recognized the Windows partition.

1 Like

Glad you figured out a solution.

Your solution seems a bit of overkill even though it worked. I think the only thing that would have been necessary would have been to run
sudo grub2-mkconfig -o /boot/grub2/grub.cfg to regenerate the grub.cfg file after the windows repair.

The error message shown in your image seems to be that windows may have created a totally new efi partition on its drive with a new UUID that grub was not aware of.