Can not boot [Esc] = no GUB menu

[steve7233]

All I get is a blank screen and one sentence "Loading Operating System ..." With a blinking underscore cursor. No error messages. How can I fix this if I can not bring up the boot menu?

[steve7233]

I was checking in my box and discovered none of the fans are running! There are lights on and the CPUs heat sink feels warm if I tap it with my finger. I turned it off and switched off the PSUs breaker switch so I could check connections. I checked the GPUs power connector and made sure the card wasn't loose from the cards MOBO socket. Checked all the three SSDs after checking power connections I tried again but still no change and I still can't bring up the GRUB menu.

[steve7233]

I found an old USB of Kubuntu 19.10 and was able to boot in to a live session. I now know my computer works so it is probably the kernel but since I can't get to the GRUB menu then how can I fix it? Since I can boot this old version then is there some way I can use it to fix the current Kubuntu? GRUB probably can't handle my Logitech multi device dongle. I don't have a wired keyboard to try.
You would think the GRUB II project would have updated by now since wireless keyboards have been a thing for several years.

[steve7233]

Where is Scotty - Star Trek -, when you need him?

[steve7233]

Strange while using Dolphin to try to find a file I could edit to make the Grub menu appear on the normal system so I could select the previous kernel I discovered I could access a SSD that the normal system can't!

[Schwarzer Kater]

We need to know a lot more to be able to help, e.g.:
What did you exactly do before the problem occured?
What is the detailed partition layout of the drive you try to boot from?
Does your computer use "legacy BIOS" or UEFI?

Without knowing any details my first impulse would be to try to chroot into the system (from another one) to reinstall GRUB to the drive.
And because I am lazy I would use the "Rescue Mode" of a Debian installation DVD to do so - but of course I have documented every single installation of my computers here and I know exactly what partition layout each drive has…
And I always have a wired keyboard on hand to exclude this as a source of trouble when I have to press keys (e.g. to get into a computer's BIOS/UEFI or to get a GRUB menu).

[steve7233]

I found a wired/wireless keyboard but the escape key still doesn't bring up the GRUB menu. Ctrl alt del works. It booted last night. I also updated before shutting down so the update probably joked something. I do not remember if it is EFI but I never have to do anything when I do a fresh Kubuntu install.

[steve7233]

No DVD or CD on this machine. Only USB.No partitions. All BTRFS.

[Schwarzer Kater]

No DVD or CD on this machine. […]

If you are refering to

"Rescue Mode" of a Debian installation DVD

-> this is no actual DVD but an ISO you can put onto a USB stick, of course (https://cdimage.debian.org/debian-cd...amd64/iso-dvd/).
I should have written "… DVD image".

[…] No partitions. All BTRFS.

Highly unlikely. Unless it is a "legacy BIOS" installation - and even then…

And unfortunately Btrfs can be a special case when rescuing a system from outside…

[steve7233]

If you are refering to -> this is no actual DVD but an ISO you can put onto a USB stick, of course (https://cdimage.debian.org/debian-cd...amd64/iso-dvd/).
I should have written "… DVD image".



Highly unlikely. Unless it is a "legacy BIOS" installation - and even then…

And unfortunately Btrfs can be a special case when rescuing a system from outside…

I meant BTRFS is a partionless file system. It is a COW or copy on write system.

[steve7233]

Since I am using a USB stick with the Kubuntu live 19.10 on it then can't I just do ctrl alt t and sudo chroot something grubreistall or whatever the command is to re install the grub II launcher? I just need to know the format for a BTRFS root system then I can use Dolphin to find the /@ file and the /@home file.

[steve7233]

I found a program called supergrub boot but it can't read my hd0 even though Dolphin reads it with no problem! It is the latest version with the number 2on the end of the file name.

[steve7233]

At the GRUB rescue prompt

set

shows cmdpath=(hd0) prefix=(hd0,msdos1)/boot/grub root=hd0,msdos1

ls

shows a blank line. Remember I am using BTRFS file system on all SSDs.

[steve7233]

I found another program to try. Boot Repair. It gets a little further but keeps generating errors. CHS AND EDD errors. It looks like sector read errors but I can read all the drives in the Kubuntu live is season via Dolphin just fine. I wonder if some BTRFS tools are not working properly. That is just a guess based on the observed results.

[jlittle]

Remember I am using BTRFS file system on all SSDs.

Partition-less btrfs on all SSDs? Grub booting from what was called the MBR gap? IMO that's a way to live dangerously; the Arch wiki says "GRUB strongly discourages installation to a partitionless disk".

It seems the computer has booted grub from the space btrfs has left for a boot loader, but that grub can't now see anything.

I suggest installing an OS to a flash drive and getting a boot from that. Note I mean install, not just write an iso to it. I've seen posts from people who do this routinely. Then, persuade grub on that flash drive to boot into your Kubuntu from a btrfs.