7

I've got this error when I try to boot my desktop up.

/tmp/mountroot-fail-hooks.d//scripts/init-premount/lvm2: No such file or directory

I'm running "on the metal" or whatever, no dual-boot anything.

I recently upgraded to 20.04 LTS from 18.04 LTS, but it ran fine until I started upgrading things and ran "autoclean", then reset.

I read that I should try for the Grub menu, and tried pressing ESC at the 5 dots loading screen, but holding it down just made it flicker between some kind of commandline / terminal, and the 5 dots.

I tried pressing ESC and holding C or any of the SHIFT keys during the terminal...

None of those got me to the Grub menu, whose appearance I looked up.

Oooh... Trying the "normal" command and hitting ESC while it was running got me to the GRUB Menu! Unfortunately, even doing the safe-mode parallel and running the package restorer didn't help.


How do I get to the Grub menu on 20.04 LTS Ubuntu?

2
  • If at 5 dots it usually is too late. You use Escape key after UEFI screen but before grub normally shows. Or if BIOS you press an hold shift key from BIOS screen until grub menu loads. If you have UEFI fast boot on, you may not have time to press any key. And if you changed grub timeout to 0 you may not be able to get grub menu.
    – oldfred
    May 22, 2020 at 2:37
  • @oldfred - I'll take that as an answer... I had a UEFI boot I could wait to fail, and hit ESC to get to Grub Command line. Now I just gotta figure out what to do to keep my stuff...
    – Malady
    May 22, 2020 at 13:38

1 Answer 1

9

If at 5 dots it usually is too late.

You use Escape key after UEFI screen but before grub normally shows.
Or if BIOS you press an hold shift key from BIOS screen until grub menu loads.

If you have UEFI fast boot on, you may not have time to press any key.
And if you changed grub timeout to 0 you may not be able to get grub menu.

Cold boot or full power down, may then then have system go back thru the full POST and give you just enough time to press keys.

If grub timeout at zero, check Boot-Repair's advanced options or a full reinstall of grub.

https://help.ubuntu.com/community/Boot-Repair

https://sourceforge.net/p/boot-repair/home/Home/

2
  • What's UEFI Fast Boot? That means skipping the Device Manufacturer info, right?
    – Malady
    May 22, 2020 at 21:39
  • 1
    Not exactly. UEFI (or BIOS) scan system for what hardware you have and write that to drive for operating system to use. Fast boot skips scan and assumes everything is the same, so you do not need scan. But if something has changed you can have issues. And without scan & write, boot is a lot faster, often not enough time to press any key to get into UEFI to make changes. You have to "cold" boot from full power down to force full scan of system again.
    – oldfred
    May 23, 2020 at 2:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.