My system runs Ubuntu 21.04. I recently moved the system from an old SSD to a new M.2 drive, using Clonezilla. In that process, I needed to run update-grub. The system boots up fine, but I cannot choose to boot the Windows 10 install I have on another drive, it is not in the grub menu when booting.
os-prober and update-grub both seem to find it no problem: root@zap:/# os-prober /dev/sdb1@/efi/Microsoft/Boot/bootmgfw.efi:Windows Boot Manager:Windows:efi root@zap:/# root@zap:/# root@zap:/# update-grub Sourcing file `/etc/default/grub' Sourcing file `/etc/default/grub.d/init-select.cfg' Generating grub configuration file ... Found linux image: /boot/vmlinuz-5.11.0-38-generic Found initrd image: /boot/initrd.img-5.11.0-38-generic Found linux image: /boot/vmlinuz-5.11.0-37-generic Found initrd image: /boot/initrd.img-5.11.0-37-generic Found linux image: /boot/vmlinuz-4.13.0-37-generic Found initrd image: /boot/initrd.img-4.13.0-37-generic Found linux image: /boot/vmlinuz-4.13.0-36-generic Found initrd image: /boot/initrd.img-4.13.0-36-generic Found Windows Boot Manager on /dev/sdb1@/efi/Microsoft/Boot/bootmgfw.efi Adding boot menu entry for UEFI Firmware Settings done root@zap:/# What have I forgotten?
11 Answer
TL'DR:
sudo echo GRUB_DISABLE_OS_PROBER=false >> /etc/default/grub && sudo update-grub Details:
OS Prober no longer ran by default in latest grub:
Warning: os-prober will not be executed to detect other bootable partitions. Systems on them will not be added to the GRUB boot configuration. Check GRUB_DISABLE_OS_PROBER documentation entry
Such kind of questions starts to show up since May 2021.
So I've followed the advice:
% sudo echo GRUB_DISABLE_OS_PROBER=false >> /etc/default/grub && sudo update-grub Sourcing file `/etc/default/grub' Sourcing file `/etc/default/grub.d/init-select.cfg' Sourcing file `/etc/default/grub.d/lubuntu-grub-theme.cfg' Generating grub configuration file ... Found theme: /usr/share/grub/themes/lubuntu-grub-theme/theme.txt Found linux image: /boot/vmlinuz-5.13.0-19-generic Found initrd image: /boot/initrd.img-5.13.0-19-generic Found Windows Boot Manager on /dev/nvme0n1p1@/EFI/Microsoft/Boot/bootmgfw.efi Found Ubuntu 20.04 LTS (20.04) on /dev/nvme0n1p6 Adding boot menu entry for UEFI Firmware Settings done $ tail -1 /etc/default/grub GRUB_DISABLE_OS_PROBER=false $ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 21.10 Release: 21.10 Codename: impish $ os-prober /dev/nvme0n1p1@/EFI/Microsoft/Boot/bootmgfw.efi:Windows Boot Manager:Windows:efi /dev/nvme0n1p6:Ubuntu 20.04 LTS (20.04):Ubuntu:linux grep menuentry /boot/grub/grub.cfg Now I can see my Ubuntu 20.04 LTS boot entries in my /boot/grub/grub.cfg file, as well as Windows boot entry:
$ grep 'menuentry.*Windows' /boot/grub/grub.cfg menuentry 'Windows Boot Manager (on /dev/nvme0n1p1)' --class windows --class os $menuentry_id_option 'osprober-efi-C633-8883' { HTH
