Arch Linux

RoniBoni

Member

Registered: 2017-09-05

Posts: 11

[SOLVED] Dual Boot Arch with Ubuntu Studio

Hello guys,
I'd like to install Ubuntu Studio in Addition to my existing Arch installation. I need a rt-Kernel, however, installing linux-rt in Arch would blow up my graphics driver since its only 4.11 at this point.
So i have a nvme drive and a regular hdd. arch is installed on the nvme using systemd-boot. I partitioned the hdd to make some room for ubuntu and installed it. During the Ubuntu installation grub was installed on the nvme. However, once i rebooted Arch started as usual. There was no grub boot menu or anything.
My question: How can i add a boot-entry for the ubuntu installation? I have an entry for arch located in /boot/loader/entries called arch.conf with the following content:

title Arch Linux
linux /vmlinuz-linux
initrd /initramfs-linux.img
options root=PARTUUID=myRootPartUuid

I tried adding a file called ubuntu.conf with exactly the same lines, just modifying the root partuuid. This didn't work. It tried loading the hdd-partition as root but something in sbin was missing. Therefore i had to boot from my arch usb-drive, mount root and boot and deleting the ubuntu.conf since tty was disabled.

I still want to be able to boot into the ubuntu installation... how can i do so?

Thanks in advance

Last edited by RoniBoni (2017-09-10 18:56:22)

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,722

Re: [SOLVED] Dual Boot Arch with Ubuntu Studio

I think you are trying to over complicate this.  There is noting wrong with having multiple kernels on the boot partition.  You can select which kernel you want at boot time in the boot loader.  Generally, one would not want to use an Arch Kernel with Ubuntu, or vice-versa. You specify the kernel on the 'linux' line of the Grub entry.   In addition, the Ubuntu system will undoubtedly have its own initial RAM file system image (initramfs).

What you have done is load the Arch Kernel and the Arch RAM FS, but used the Ubuntu root.  The biggest problem is that the Arch Kernel is named differently and has a different version than does the Ubuntu kenrel.  The Arch kernel cannot find its modules and goes stupid on you.

Set up Arch the way you really want it.
Copy the Ubuntu kernel and initramfs image to the boot partition and place them next to those of Arch, but with different names.
Fix the Ubuntu Grub entry to use those Ubuntu files

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The shortest way to ruin a country is to give power to demagogues.— Dionysius of Halicarnassus
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RoniBoni

Member

Registered: 2017-09-05

Posts: 11

Re: [SOLVED] Dual Boot Arch with Ubuntu Studio

I naively thought when i give the root partition it would find the corresponding initramfs and vmlinuz. But they are actually named differently. Thx for clarifying.
But i dont boot from grub atm. I see the systemd boot stuff when i turn my computer on. Do i really need to mess around with grub? My thought was adding a .conf file in /boot/loader/entries like i did for arch. i just need to rename the linux and initramfs i think? So something like:

title ubuntu studio
linux /vmlinuz-4.10.0-28-lowlatency
initrd /initrd.img-4.10.0-28-lowlatency
options root=PARTUUID=thePartUUIDfromTheHDDpartition

would do it?

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,722

Re: [SOLVED] Dual Boot Arch with Ubuntu Studio

Sorry, lack of coffee this morning.  I read that as being a grub configuration file.  No, no need to mess with Grub.  I personally think Grub is an overkill for the vast majority of systems.

Yes, all you need to is adjust the systemd-boot configuration that you posted.

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Nothing is too wonderful to be true, if it be consistent with the laws of nature -- Michael Faraday
The shortest way to ruin a country is to give power to demagogues.— Dionysius of Halicarnassus
---
How to Ask Questions the Smart Way

RoniBoni

Member

Registered: 2017-09-05

Posts: 11

Re: [SOLVED] Dual Boot Arch with Ubuntu Studio

Oh wow, it actually worked. I copied the kernel and initrd files to /boot and wrote a ubuntu.conf in /boot/loader/entries.
Ubuntu booted, excellent.
But there is no Boot menu, it just immediately starts ubuntu. So i thought, maybe i should delete the ubuntu.conf and append its lines to my arch.conf.
This results in still no boot menu. Ubuntu tries to start (cant find initrd files, maybe a typo, but thats not the point).
How do i get a boot menu? Or do i need to press some buttons after my board POSTs?
Thx for the help, i really learned something about systemd boot today i hope you can help me to solve my last problem too.

Slithery

Administrator

From: Norfolk, UK

Registered: 2013-12-01

Posts: 5,776

Re: [SOLVED] Dual Boot Arch with Ubuntu Studio

This is all in the wiki...

https://wiki.archlinux.org/index.php/Sy … figuration

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No, it didn't "fix" anything. It just shifted the brokeness one space to the right. - jasonwryan
Closing -- for deletion; Banning -- for muppetry. - jasonwryan

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frosth

Member

Registered: 2010-02-13

Posts: 17

Re: [SOLVED] Dual Boot Arch with Ubuntu Studio

Ubuntu's grub is in UEFI or BIOS mode?
edit:
Uhh it's the same disk so probably they both on UEFI
You should have /boot/EFI/ubuntu/grubx64.efi (only if you mount your ESP in /boot)

add ubuntu.conf in /boot/loader/entries/

title  Ubuntu Studio
efi    /EFI/ubuntu/grubx64.efi

it should switch to normal Ubuntu Grub session.

Last edited by frosth (2017-09-10 19:06:45)

RoniBoni

Member

Registered: 2017-09-05

Posts: 11

Re: [SOLVED] Dual Boot Arch with Ubuntu Studio

That's right. I was a little bit confused. There was a Timer set to 3. but it was commented out with a #symbol...
well, it works now, Thanks a lot! I'm smarter now.