install different linux distro alongside existing

[ValentynPrumers]

Hi!

I have installed kubuntu on my laptop using my entire hard drive. The installation process created 2 partitions. A fat32 /boot/efi and an ext4 / partition.

Now i want to try a different linux distro. But i dont want to lose my kubuntu. How do i approach this best?

Thanks

[Rubi1200]

Backups, backups, backups BEFORE making any changes to drives/partitions.

Easiest way is to use pretty much any liveUSB that has GParted installed and use it to shrink the Kubuntu partition to make room for the new distro.

Two main things to be aware of:
1. you will likely need to do a manual install to make sure the new distro is pointed at the new partition you created
2. the new distro will install GRUB and be the one that controls booting not the GRUB of the Kubuntu install

How large is the hard drive and what is the new distro you want to install?

[oldfred]

Note if Ubunutu flavor or even based on Ubuntu it probbly will use the same installer & UEFI boot entry.
So you will only have one "ubuntu" entry in UEFI.
But grub should let you boot any install as long as installs are in same boot mode or all UEFI.

If you want your Kubuntu to be default, easiest way is just to boot into Kubuntu and reinstall grub.
sudo grub-install

You can manually edit /EFI/ubuntu/grub.cfg which has UUID of install it will use to boot into.
But Ubuntu locks ESP with mount in fstab. You can edit from live installer, or change defaults in fstab (but less security).

If not based on Ubuntu, then you probably get a grub or name of distribution as boot entry in UEFI. It will be default but you can easily change boot order in UEFI with efibootmgr & -o parameter.
see
man efibootmgr
sudo efibootmgr -v # to see current order
sudo efibootmgr -o x,y,z

[ValentynPrumers]

Backups, backups, backups BEFORE making any changes to drives/partitions.

Easiest way is to use pretty much any liveUSB that has GParted installed and use it to shrink the Kubuntu partition to make room for the new distro.

Two main things to be aware of:
1. you will likely need to do a manual install to make sure the new distro is pointed at the new partition you created
2. the new distro will install GRUB and be the one that controls booting not the GRUB of the Kubuntu install

How large is the hard drive and what is the new distro you want to install?

Drive is 1TB, new system is Kali linux.

Can't i use KDE partition manager to shrink the current / partition ? Or cant i do that because its mounted?

[1fallen]

Or cant i do that because its mounted?

That's a good guess, no partition tool will touch a mounted drive.

[Rubi1200]

Drive is 1TB, new system is Kali linux.

Can't i use KDE partition manager to shrink the current / partition ? Or cant i do that because its mounted?

You cannot modify mounted drives/partitions No tool will allow that.

If I am not mistaken Kali should come with GParted. Boot it as a live medium and make the relevant changes to create space for the new install.

[Frogs Hair]

You can get look at many distros via web browser. They have a pretty good selection at the link.

https://distrosea.com/

[yancek]

Since you appear to have a very limited knowledge in this regard, you might try installing Kali in virtual software or to a usb drive as explained in detail at the Kali site.

[MAFoElffen]

I would recommend the same.

Kali is Debian-based... so similar to a point. If it uses the old Ubiquity installer... Then after booting the live installer media in Try mode, you could use the command

ubiquity -b

To start the installer without installing Grub... Then after the install, modify the /etc/default/grub file in your pre-existing Ubuntu Install, GRUB_DISABLE_OS_PROBER line to "false" to try to pick it up in the Grub2 menu. (***)

I've done that in the past. Otherwise, I find if I want to try out multiple Distro's... If I don't necessarily need direct hardware access with that (I rarely do these days), then I install it as a VM Guest in KVM. That makes things more flexible and controllable. With KVM, I can also dynamically give it access to some hardware resources.

I used to do Contract IT Services, which Network Support was part of that. Kali runs well as a VM. Think also about learning WireShark, and building network taps & modular cable adapters. All of that was my go-to's on my laptop going onsite somewhere to diagnose problems.

NOTES:
*** - I dont know how, yet, to do this method with the new Ubuntu 'ubuntu-desktop-installer' Flutter Installer. It's default behavior is to install Grub2. I don't know yet how to turn that off. If someone has found a way to do that with the new installer. Please share that.

[ValentynPrumers]

Thanks a lot! I think i will try to install it first as VM. Do you advice KVM over VirtualBox? Ive heard there were some problems with getting the wireless network card to work on a Kali VM. Is that true, or is that fixed?

(I also might want to create a windows 10 VM while i am at it, dont know if that changes anything)