Arch Linux

gddrew

Member

Registered: 2023-08-30

Posts: 6

[SOLVED] [Windows 11 not showing in GRUB with OS-Prober

Installed Arch on a SSD hard drive with Windows 11 already installed (and Windows is not encrypted).

Details:

• Windows EFI partition resides on /dev/nvme0n1p1

• Windows OS partition on /dev/nvme0n1p3

• Linux EFI partition on /dev/nvme0n1p7

• Linux OS partition on /dev/nvme0n1p8

Steps to mount the partitions:

1. mount /dev/nvme0n1p8

2. mkdir /mnt/boot

3. mkdir /mnt/win

4. mount /dev/nvme0n1p7 /mnt/boot

5. mount /dev/nvme0n1p1 /mnt/win[/*]

After installing base system et al, I install GRUB and the bootmanager packages, along with support for the NTFS file system:

pacman -S grub dosfstools os-prober mtools efibootmgr ntfs-3g

Next, edit grub and uncomment the GRUB_DISABLE_OS_PROBER= false line.
Run

grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id=Arch

.
Then to create the grub config

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

Reboot, but Windows isn't in the menu.

What have I done wrong?

Last edited by gddrew (2023-09-26 16:23:17)

gddrew

Member

Registered: 2023-08-30

Posts: 6

Re: [SOLVED] [Windows 11 not showing in GRUB with OS-Prober

Output of fstab:

#<file system> <dir> <type> <options> <dump> <pass>
# /dev/nvme0n1p8
UUID=16df2b60-31c5-4cbc-8686-3b55a0519b1f.     /       ext4              rw,realtime     0 1

# /dev/nvme0n1p7
UUID-15A0-F0A7          /boot          vfat     rw,relatime, fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro   0 2

# /dev/nvme0n1p1 LABEL=ESP
UUID-0A03-1A98         /win            vfat     rw,relatime, fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro   0 2

gddrew

Member

Registered: 2023-08-30

Posts: 6

Re: [SOLVED] [Windows 11 not showing in GRUB with OS-Prober

According to the Wiki article regarding dual boot with Windows, you should not create a separate EFI partition for Linux as that may cause Windows not to boot. The preferred method is to use the existing EFI system partition that Windows created.

I therefore used GParted to resize that partition from 500M to 1000Gib, then repeated the install process, but still not finding the Windows partition.

The upshot is I ran blkid to get the UUID of the EFI system partition, put the entry in /etc/fstab, and ran the grub mkconfig command again. After that the partition appeared in the grub menu.