Unix & Linux
boot grub2 dual-boot uefi
Updated Mon, 02 May 2022 07:53:14 GMT

Can't boot on Win10 with dual-boot Fedora 29 + Win10 (both encrypted partitions)

Did install Fedora 29 on a different partition than Win10, usual dual boot configuration that I already used a good number of times.

The new parameter is that I use encryption on Windows system (Bitlocker).

When choosing Win10 from the GRUB menu, I get this error message from GRUB:

error: ../../grub-core/net/net.c:1390:no server is specified.
Press any key to continue...

And this obviously gets me back to the GRUB menu.

Fedora boot is working fine.

I can properly boot in Win10 by skipping GRUB (choosing UEFI boot on Windows partition from the BIOS).

My GRUB config for the Win10 boot is:

insmod part_gpt
insmod fat
set root=/dev/nvme0n1p2
chainloader /EFI/Microsoft/Boot/bootmgfw.efi


Turns out having dual-boot with UEFI needs a different setup:

  • /boot on a separate unencrypted ext4 partition (1GiB is good).
  • /boot/efi entry point set on the boot partition already created by Windows.

Warning, Bitlocker will ask for the recovery key on the first boot because settings have changed.

Then, with a TPM, no password asked on next reboots.

Good article with explanations, and a detailed answer for Fedora.