And now, for the long awaited sequel to "botched Ubuntu update": "Botched grub config"!

[yuki2501@masto.hackers.town]

And now, for the long awaited sequel to "botched Ubuntu update": "Botched grub config"!

I had tried to add a GRUB_BADRAM parameter to my grub environment and it failed spectacularly: Now NOTHING BOOTS! Not even the grub prompt!

I managed to find an old Kubuntu 19 boot USB and managed to remove the offending line from the grub text config (under /etc/grub) file in my HDD.

But now I don't know how to update grub under /boot...

Edit: SOLVED!

#LinuxHelp

[sys64738@www.librepunk.club]

@yuki2501 temporarily manually edit the grub config in your root partition to do the proper thing on your actual daily driver computer (whle booted into kubuntu 19), then boot into the normal install on your daily driver machine, and re-regenerate the grub config from there?

[yuki2501@masto.hackers.town]

@sys64738 but I can't boot the normal install until the grub config is updated under /boot/grub (I only edited the grub config under /etc/grub). The update part is what I need to do.

[sys64738@www.librepunk.club]

@yuki2501 yes, connect the drive onto kubuntu 19 machine, mount its /boot partition somewhere, and edit the grub config there manually so you can boot your regular linux install

[sys64738@www.librepunk.club]

@yuki2501 alternatively, with the 'e' key you can edit a grub boot option so you can do a one-time edit to make it boot maybe?

[yuki2501@masto.hackers.town]

@sys64738 It seems that I couldn't communicate my situation correctly.

The editing part is easy. Already mounted and everything. How do I tell grub-update to compile the configs and generate the boot files in media/originalpartition while my root is from the USB thumb drive?

[sys64738@www.librepunk.club]

@yuki2501 no, I was trying to tell you to edit the files that reside in your boot parittion and normally get generated by grub-update, so you can boot in your regular install instead to then do the fixing & running grub-update again

[sys64738@www.librepunk.club]

@yuki2501 this would sidestep the entire "what does grub think my root drive is" issue

[yrabbit@mastodon.sdf.org]

@yuki2501
You can change root ;) you know - chroot etc

[sys64738@www.librepunk.club]

@yuki2501 but yeah as the other reply said, you can also mount hte root partition from kubuntu 19, chroot to it, mount the other partitions of that system inside the chroot, and then run grub-update

[sys64738@www.librepunk.club]

@yuki2501 (going to sleep now though, it's past 3am here. goo luck!)

[yuki@im-in.space]

@yuki2501 mount your Ubuntu install under, say, /mnt, mount your boot partition on /mnt/boot, then chroot /mnt, if you regenerate your grub config from there it should work

[yuki2501@masto.hackers.town]

I did it!!!

I followed the instructions at https://askubuntu.com/questions/145241/how-do-i-run-update-grub-from-a-livecd

and managed to restore my grub.

I can boot again!!! : 🥳