Kubuntu EFI folder.

[Rich Oliver]

In Kubuntu 25.10 the EFI data seems to be stored in a "kubuntu" folder. Kubuntu used to store its EFI data in an "ubuntu" folder. I wondered if anyone knew when that change happened.

[claydoh]

What path are you looking at?

[jlittle]

I have a tiny PC with a mostly vanilla 25.10 install, and the EFI folder is "ubuntu". If yours is indeed "kubuntu", I wonder how you achieved that.

What counts though, is the boot entry revealed by

sudo efibootmgr

Note that even if one uses efibootmgr to set a different directory, the path /EFI/ubuntu is coded inside the grubx64.efi executable.

[Rich Oliver]

I have a tiny PC with a mostly vanilla 25.10 install, and the EFI folder is "ubuntu". If yours is indeed "kubuntu", I wonder how you achieved that.

I'm wondering that now myself. That was on my desktop. I didn't think to check my laptop. Checking efibootmgr on my laptop, Kubuntu 25.10 is indeed using the "ubuntu" folder. I multi-boot multiple Linux distros plus a windows install on desktop and laptop. I only discovered it, because I'd just installed CachyOS on my desktop for the first time and the OS finder for grub is switched off by default on CachyOS, so I used efibootmgr to go back to my previous grub menu. But my desktop now definitively seems to be using a grub from the EFI/Kubuntu folder not the EFI/ubuntu folder.

So the only thing I can think is this. One of the first things I do after a Kubuntu install is go in and change /etc/default/grub and /etc/lsb-release and then update grub. I change any reference to "Ubuntu" to "Kubuntu" and then update-grub. So maybe what happened is that I installed another version of Kubuntu alongside 25.10, which would wipe out and replace the 25.10 grub. Then at some point I reinstalled the grub on 25.10 and on the reinstall it put it in the EFI/kubuntu folder leaving the other grub undeleted in the EFI/ubuntu folder.

[kc1di]

It's ubuntu on mine also. Not sure what changed yours. But as long as it works I wouldn't worry too much about it.

[claydoh]

Again, what is the full path to this directory while running Kubuntu?
The boot files have always been ubuntu and still are. Editing the contents in /etc/default/grub does not change any directory name or mount point.

What does efibootmgr actually show ?

Show us exactly what you see so we can be sure we are all on the same page. Especially as I myself tend to be in Lala land, and likely to be lost



I wonder if this is a drive or device name or label, not a physical directory. More so if you only see this from a different distro.

For example, the installer set my "/" (root) as "kubuntu_25.10":



If you click into the address bar, it should show the actual path, as seen in my first screenshot.


.

[Rich Oliver]

Again, what is the full path to this directory while running Kubuntu?
The boot files have always been ubuntu and still are. Editing the contents in /etc/default/grub does not change any directory name or mount point.

What does efibootmgr actually show ?

Sorry I've only just got back on my desktop, I was posting from laptop.

BootCurrent: 000C
Timeout: 1 seconds
BootOrder: 000C,0002,000D,0000,000E
Boot0000* Windows Boot Manager  HD(2,GPT,6887665d-8afc-4af1-9644-4f2727001055,0x109000,0x31800)/File(\EFI\MICROSOFT\BOOT\BOOTMGFW.EFI)57494e444f5753000100000088000000780000004200430044004f0042004a004500430054003d007b00390064006500610038003600320063002d0035006300640064002d0034006500370030002d0061006300630031002d006600330032006200330034003400640034003700390035007d00000074000100000010000000040000007fff0400
Boot0002* cachyos       HD(1,GPT,5ed3ce8b-58ba-4e19-a586-e719bd8d8d41,0x800,0x186000)/File(\EFI\CACHYOS\GRUBX64.EFI)
Boot000C* Kubuntu       HD(1,GPT,5ed3ce8b-58ba-4e19-a586-e719bd8d8d41,0x800,0x186000)/File(\EFI\UBUNTU\SHIMX64.EFI)
Boot000D* ubuntu        HD(2,GPT,6887665d-8afc-4af1-9644-4f2727001055,0x109000,0x31800)/File(\EFI\UBUNTU\SHIMX64.EFI)0000424f
Boot000E* debian        HD(2,GPT,6887665d-8afc-4af1-9644-4f2727001055,0x109000,0x31800)/File(\EFI\DEBIAN\GRUBX64.EFI)0000424f

So you are right there is no EFI/Kubuntu folder. I saw the entry labeled as "kubuntu" and just presumed that it must be in a EFI/kubuntu folder, because before Linux grub data had always been in folder with the same name as the efibootmgr label. Apologies for spreading FUD.

[jlittle]

I multi-boot multiple Linux distros plus a windows install on desktop and laptop.

IMO if you do that it's far more reliable to manually maintain an independent grub install and turn off the update-grub machinery where possible.

[oshunluvr]

This is the way

[Rich Oliver]

I was doing regular Kubuntu installs, with manual partitioning for years on my own machines and others. But some time back the Kubuntu installer changed and I got somewhat confused. The installer requires you to label the uefi partition as an efi and a boot partition. Although as a far as I understand it the boot directory is still installed on the root partition unless specifically mounted otherwise. I've been currently labeling both the root and uefi partitions as boot partitions. I don't know if that is the correct thing to do.

What also seemed to change, is that if you reformat the UEFI partition previous kubuntu installs now t seem to stop working.

[Rich Oliver]

IMO if you do that it's far more reliable to manually maintain an independent grub install and turn off the update-grub machinery where possible.

I played around with Arch some time back, but never actually did a grub install for Arch, just piggybacking off another distro's grub. I'll play around with Catchy for a bit, see if I can use it for work and then I'll go back and try and do a proper raw Arch install with grub. just to say what ever distoro, I've always been a loyal KDE user.

[oshunluvr]

I played around with Arch some time back, but never actually did a grub install for Arch, just piggybacking off another distro's grub. I'll play around with Catchy for a bit, see if I can use it for work and then I'll go back and try and do a proper raw Arch install with grub. just to say what ever distoro, I've always been a loyal KDE user.

As jlittle suggests, if you regularly boot different distros and.or like to try out other distros occasionally, it's much safer to have a stand-alone distro that manages GRUB. IMO it's too easy to "forget" which install is responsible for GRUB. If you remove that particular distro, you can't boot anything on your drive until you repair and replace GRUB, and Yes I've done this more than once

My setup is to use Ubuntu server with no desktop or really anything else added as my default boot distro. It's less than 4GB.

Then I use the /etc/grub.d/40_custom file to boot other installs by using the GRUB.CFG from the install I'm booting to. Here's and example boot stanza from my system:

menuentry 'Kubuntu 24.04' --class kubuntu {
    insmod part_gpt
    insmod btrfs
    search --no-floppy --fs-uuid --set=root 247e6a5b-351d-4704-b852-c50964d2ee6
    configfile /@kubuntu2404/boot/grub/grub.cfg
}

Each time I do a new install, I have it install GRUB but to a partition (or second drive works too). That way it creates and maintains it's own grub.cfg but never actually takes over grub on the boot drive.

[Rich Oliver]

IMO it's too easy to "forget" which install is responsible for GRUB. If you remove that particular distro, you can't boot anything on your drive until you repair and replace GRUB, and Yes I've done this more than once

Ah well that's why I change the grub and the lsb_release files as one of my first priorities. That way I know exactly what distro, what version, is the top default grub option and what partition the root is mounted. The default set up gives you this information for the other operating systems but not the top / default grub option.

What I think I've been too lax on, is deleting defunct efiboot entries. Looking at the documentation for grub-install, it says you don't even need to indicate the drive as long as /boot/efi partition is properly mounted. What I couldn't seem to find was an option to set the folder name within the /boot/efi/EFI directory.