update grub2 issue
 

I waited almost a year before upgrading my laptop and desktop to 22.04lts to avoid the update blues. However after using Linux operating Systems since 2206 without issue... I blew it! My lap top upgraded through the internet but my Dell Optiplex 7010 refused to upgrade this way. I downloaded 22.04 and did a fresh install. However my Fedora 36 on the Dell Tower is not listed in the boot screen GRUB. I have tried updating grub2 in the terminal but Fedora is not found.

When I search the files, the Fedora files appear to be the same as on my T420 lap top. Any help, after almost7 months will be appreciated.

Bill Taylor
Killer Spade 806
Vietnam

add GRUB_DISABLE_OS_PROBER=false to /etc/default/grub and/or remove the # at the beginning of the line if it exist and rerun update-upgrade

Thank you, Brother. I knewit was simple but I failed to find it.

What cold possibly be the motivation for a default like that ?.

To disable os_prober? Under some storage configurations it can hang and never complete. I had such an instance years back with Tumbleweed using LVM+ext4 instead of btrfs (the default, I was stubborn about btrfs at the time). os_prober would always hang during detection of the lvm volumes, and I could never update kernels until I reinstalled.

add a chainloader entry to /etc/grub.d/40_custom similar to this:
and run update-grub. This is assuming the system is a uefi system and the efi partition is the first partition of the first drive.

Never had a problem. All my systems are multi-boot (not dual) - I would be seriously cranky with this as a default.