GRUB not detecting Windows,but os-prober does

mainpin442 · 2022-10-14 18:43:56

Hello everyone,
I had Arch Linux installed for half a year on my computer, with only one drive. A few days ago, I bought a new one and tried to dualboot Arch and Windows. Expecting Windows to cause problems, I downloaded Arch ISO and Windows ISO on my USB using Ventoy.
Despite the fact that I installed Windows on the new drive, GRUB worked the same as before,but it didn't detect Windows, so I modified /etc/default/grub to enable os-prober and then ran sudo grub-mkconfig /boot/efi/grub/grub.cfg. After that I was unable to even access GRUB, and had to boot from USB and follow this guide on fixing the problem. After that, I am again in the same spot now, even after manually removing my drive containing Arch and reinstalling Windows 10 on the other, this time with CSM support disabled (I am using a Gigabyte motherboard, and this is the only thing I can do, I surely hope this is not the issue), and then returning the Arch drive and reinstalling GRUB AGAIN.

Here's all the info:

fdisk -l:

Disk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors
Disk model: Samsung SSD 870 
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 9259D311-9EE9-440E-9171-492779A6A023

Device          Start        End    Sectors   Size Type
/dev/sda1        2048     206847     204800   100M EFI System
/dev/sda2      206848     239615      32768    16M Microsoft reserved
/dev/sda3      239616 1952462447 1952222832 930.9G Microsoft basic data
/dev/sda4  1952462848 1953521663    1058816   517M Windows recovery environment


Disk /dev/nvme0n1: 465.76 GiB, 500107862016 bytes, 976773168 sectors
Disk model: KINGSTON SNVS500G                       
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 9C728531-5588-4462-B1E5-901D5E51CC85

Device           Start       End   Sectors   Size Type
/dev/nvme0n1p1    2048   1048575   1046528   511M EFI System
/dev/nvme0n1p2 1050624 976773119 975722496 465.3G Linux filesystem


Disk /dev/zram0: 4 GiB, 4294967296 bytes, 1048576 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

os-prober:

/dev/sda1@/efi/Microsoft/Boot/bootmgfw.efi:Windows Boot Manager:Windows:efi

cat /etc/grub.d/40_custom (I tried...):

#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
menuentry 'Windows' {
        search --set=root --file /efi/Microsoft/Boot/bootmgfw.efi
        chainloader /EFI/Microsoft/Boot/boottmgfw.efi
}

cat boot/efi/grub/grub.cfg:

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
insmod part_gpt
insmod part_msdos
if [ -s $prefix/grubenv ]; then
  load_env
fi
if [ "${next_entry}" ] ; then
   set default="${next_entry}"
   set next_entry=
   save_env next_entry
   set boot_once=true
else
   set default="0"
fi

if [ x"${feature_menuentry_id}" = xy ]; then
  menuentry_id_option="--id"
else
  menuentry_id_option=""
fi

export menuentry_id_option

if [ "${prev_saved_entry}" ]; then
  set saved_entry="${prev_saved_entry}"
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z "${boot_once}" ]; then
    saved_entry="${chosen}"
    save_env saved_entry
  fi
}

function load_video {
  if [ x$feature_all_video_module = xy ]; then
    insmod all_video
  else
    insmod efi_gop
    insmod efi_uga
    insmod ieee1275_fb
    insmod vbe
    insmod vga
    insmod video_bochs
    insmod video_cirrus
  fi
}

if [ x$feature_default_font_path = xy ] ; then
   font=unicode
else
insmod part_gpt
insmod ext2
search --no-floppy --fs-uuid --set=root c1338628-bc8f-4da1-a4ef-8df0a8e80ed6
    font="/usr/share/grub/unicode.pf2"
fi

if loadfont $font ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  set locale_dir=$prefix/locale
  set lang=en_US
  insmod gettext
fi
terminal_input console
terminal_output gfxterm
if [ x$feature_timeout_style = xy ] ; then
  set timeout_style=menu
  set timeout=5
# Fallback normal timeout code in case the timeout_style feature is
# unavailable.
else
  set timeout=5
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/10_linux ###
menuentry 'Arch Linux' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-c1338628-bc8f-4da1-a4ef-8df0a8e80ed6' {
        load_video
        set gfxpayload=keep
        insmod gzio
        insmod part_gpt
        insmod fat
        search --no-floppy --fs-uuid --set=root B9F6-9BB0
        echo    'Loading Linux linux ...'
        linux   /vmlinuz-linux root=UUID=c1338628-bc8f-4da1-a4ef-8df0a8e80ed6 rw rootfstype=ext4 loglevel=3 quiet
        echo    'Loading initial ramdisk ...'
        initrd  /amd-ucode.img /initramfs-linux.img
}
submenu 'Advanced options for Arch Linux' $menuentry_id_option 'gnulinux-advanced-c1338628-bc8f-4da1-a4ef-8df0a8e80ed6' {
        menuentry 'Arch Linux, with Linux linux' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-advanced-c1338628-bc8f-4da1-a4ef-8df0a8e80ed6' {
                load_video
                set gfxpayload=keep
                insmod gzio
                insmod part_gpt
                insmod fat
                search --no-floppy --fs-uuid --set=root B9F6-9BB0
                echo    'Loading Linux linux ...'
                linux   /vmlinuz-linux root=UUID=c1338628-bc8f-4da1-a4ef-8df0a8e80ed6 rw rootfstype=ext4 loglevel=3 quiet
                echo    'Loading initial ramdisk ...'
                initrd  /amd-ucode.img /initramfs-linux.img
        }
        menuentry 'Arch Linux, with Linux linux (fallback initramfs)' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-fallback-c1338628-bc8f-4da1-a4ef-8df0a8e80ed6' {
                load_video
                set gfxpayload=keep
                insmod gzio
                insmod part_gpt
                insmod fat
                search --no-floppy --fs-uuid --set=root B9F6-9BB0
                echo    'Loading Linux linux ...'
                linux   /vmlinuz-linux root=UUID=c1338628-bc8f-4da1-a4ef-8df0a8e80ed6 rw rootfstype=ext4 loglevel=3 quiet
                echo    'Loading initial ramdisk ...'
                initrd  /amd-ucode.img /initramfs-linux-fallback.img
        }
}

### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows Boot Manager (on /dev/sda1)' --class windows --class os $menuentry_id_option 'osprober-efi-6E66-76D8' {
        insmod part_gpt
        insmod fat
        set root='hd0,gpt1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1  6E66-76D8
        else
          search --no-floppy --fs-uuid --set=root 6E66-76D8
        fi
        chainloader /efi/Microsoft/Boot/bootmgfw.efi
}
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/30_uefi-firmware ###
fwsetup --is-supported
if [ "$grub_platform" = "efi" -a "$?" = 0 ]; then
        menuentry 'UEFI Firmware Settings' $menuentry_id_option 'uefi-firmware' {
                fwsetup
        }
fi
### END /etc/grub.d/30_uefi-firmware ###

### BEGIN /etc/grub.d/35_fwupd ###
### END /etc/grub.d/35_fwupd ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
menuentry 'Windows' {
        search --fs-uuid --set=root /dev/sda1 19259d311-9ee9-440e-9171-492779a6a023
        chainloader /EFI/Microsoft/Boot/boottmgfw.efi
}
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f  ${config_directory}/custom.cfg ]; then
  source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f  $prefix/custom.cfg ]; then
  source $prefix/custom.cfg
fi
### END /etc/grub.d/41_custom ###

sudo grub-mkconfig -o /boot/efi/grub/grub.cfg:

Generating grub configuration file ...
Found linux image: /boot/vmlinuz-linux
Found initrd image: /boot/amd-ucode.img /boot/initramfs-linux.img
Found fallback initrd image(s) in /boot:  amd-ucode.img initramfs-linux-fallback.img
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Found Windows Boot Manager on /dev/sda1@/efi/Microsoft/Boot/bootmgfw.efi
Adding boot menu entry for UEFI Firmware Settings ...
done

Any help would be appreciated, thanks in advance.

Last edited by mainpin442 (2022-10-14 18:45:51)

Maniaxx · 2022-10-14 19:11:14

You probably have mixed up (new) grub config and (old) runtime files. See here.

cfr · 2022-10-14 23:31:01

What's the output of efibootmgr?

Exactly what commands did you use when installing grub?

Having two ESPs can cause issues, although my impression is most firmware tolerate them.

Arch Linux

#1 2022-10-14 18:43:56

GRUB not detecting Windows,but os-prober does

#2 2022-10-14 19:11:14

Re: GRUB not detecting Windows,but os-prober does

#3 2022-10-14 23:31:01

Re: GRUB not detecting Windows,but os-prober does

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