GRUB Woes

[Geoff_Lane]

Folks,

How can I disable all GRUB menu entries except the Custom Entries?

update-grub grub-mkconfig and grub-install are giving me nightmares when I try to tidy up the menu on an external drive, I've somehow ended up losing GRUB from my main internal drive although I did not knowingly touch it, drive letters change depending on which one boots. Had to reinstall GRUB to internal drive and now all OK - except for the untidy menu.

I'd just like to use Custom Menu only.

Would it be merely change the permissions to scripts in /etc/grub.d/ ?

Geffers

[Dennis N]

How can I disable all GRUB menu entries except the Custom Entries?

It's done with changing permissions of files in /etc/grub.d

Most important is to make 30_os-prober non-executable.
For strictly custom menu entries only, you can do the same with 10_linux and 20_memtest86+, but I opt to leave these alone.

Run sudo update-grub after changes.

[Geoff_Lane]

It's done with changing permissions of files in /etc/grub.d

Most important is to make 30_os-prober non-executable.
For strictly custom menu entries only, you can do the same with 10_linux and 20_memtest86+, but I opt to leave these alone.

Run sudo update-grub after changes.

Thank you, will do so now.

Geoff

[oldfred]

UEFI or BIOS.
You do need to make sure you boot external drive from external drive.
Default install using Ubuntu's Ubiquity only installs grub to first drive, usually internal drive & sda or first NVMe drive.
With BIOS you can specify during Something Else install, but that does not work with UEFI installs.

Old info, but still valid (I think). I turn off os-prober and use 40_custom, but let it find kernels in my install.
Grub2 info by ranch hand and many links to other grub2 info sites
http://ubuntuforums.org/showthread.p...11#post8191211

From Ranch hand
You only need 3 scripts for grub to tick like a clock;
00_header
05_debian-theme
06_custom (or 07, 08, 09, 25, 40)


How to: Create a Customized GRUB2 Screen that is Maintenance Free.- Cavsfan
https://help.ubuntu.com/community/Ma...tomGrub2Screen
https://www.gnu.org/software/grub/ma...-manual-config
https://help.ubuntu.com/community/Grub2/CustomMenus

[Geoff_Lane]

From Ranch hand
You only need 3 scripts for grub to tick like a clock;
00_header
05_debian-theme
06_custom (or 07, 08, 09, 25, 40)

All O/Ss are UEFI

When I had the problems identified in the other thread posted recently I merely stopped the Linux file 02 and 03 probe from running and everything went wrong from there.

My main problem is trying to understand where the grub boot-loader is getting its config files from. Every Linux distro has the same named config files, if a subsequent O/S is installed does it uses those config files or the original installation.

I have an external disk, almost without fail when I boot to it it comes up with the menu that I have on my internal drive, kill the power,restart and correct menu then appears.

Geoff

[yancek]

My main problem is trying to understand where the grub boot-loader is getting its config files from.

If all your systems are UEFI, you can have only one set to boot first from the system board and EFI partition. If you have multiple UEFI systems installed with separate directories for each on the EFI partition, you can change which boots in he BIOS firmware boot options one time only or in the BIOS firmware on a permanent basis. Methods vary with manufacturer. Each OS should have a separate directory in the EFI partition and will point to the remaining/necessary boot/grub files on the / (root filesystem) partition for that OS.

[oldfred]

May be best to see details, use ppa version with your live installer (2nd option) or any working install, not older Boot-Repair ISO:
Please copy & paste link to the Boot-info summary report ( do not post report), the auto fix sometimes can create more issues.
https://help.ubuntu.com/community/Boot-Repair &
https://sourceforge.net/p/boot-repair/home/Home/

[Geoff_Lane]

If all your systems are UEFI, you can have only one set to boot first from the system board and EFI partition. If you have multiple UEFI systems installed with separate directories for each on the EFI partition, you can change which boots in he BIOS firmware boot options one time only or in the BIOS firmware on a permanent basis. Methods vary with manufacturer. Each OS should have a separate directory in the EFI partition and will point to the remaining/necessary boot/grub files on the / (root filesystem) partition for that OS.

Thank you.

Geoff

[Geoff_Lane]

From Ranch hand
You only need 3 scripts for grub to tick like a clock;
00_header
05_debian-theme
06_custom (or 07, 08, 09, 25, 40)

I've disabled 10_linux using same command, that seems to work OK though it does find a Fedora installation, and of course Windoz (appreciate the disabled file looks for Linux) and puts both in the menu.

But if I subsequently disable probe by sudo chmod -x 30_os-prober followed by update-grub then my custom entries do not load and when I boot it goes to BIOS after a pause as it seems there are no entries to boot.

Geoff

[yancek]

Did you read post #7 above by oldfred? You indicate multi-boot but not what you are multi-booting or how many hard drives you have or how many EFI partitions or which OS is set to boot first from the BIOS. All these and more questions can be answered if you run boot repair as suggested by oldfred and post the link to the output here! Otherwise, it's just going to be a lot of guessing.