DualBoot windows/kubuntu

[jhoni146]

Hello,

I'm trying to install Kubuntu together with Windows, the problem is that apart from not being clear about the partitions, the Windows EFI partition is only 100MB and Kubuntu asks for a minimum of 300 and I can't expand it, I don't want to delete it so as not to screw up Windows startup, The other partitions I am creating are 4GB SWAP (I have 16GB of ram) and the rest of the space in ext4 in root /, I would need help to install the dual, thanks.

[oshunluvr]

Actually you should be able to install anyway. It's a warning but shouldn't fail the install.

[oshunluvr]

I just checked an EFI install in a VM and the amount used by Kubuntu is 7.7mb so you should have enough space

[jhoni146]

Then it will automatically take the existing partition, right? Are the other two partitions correct?

4GB swap (or not necessary)

and the rest of space in /

Thank you for your answers.

[oshunluvr]

SWAP partition is up to you. The installer will, or should, create a swap file if no swap partition is available. IMO, if you plan on installing additional Linux distros, a shared swap partition is useful. If you intend to only install only one Linux distro (Kubuntu in this case) then a swap file is more flexible. You can increase or decrease it's size without re-partitioning whereas a swap partition is much more difficult to modify.

As far as the remainder of the space, if you choose to use the BTRFS file system for Kubuntu then I recommend using all the available free space for the entire file system. If you choose EXT4 (the default, old, and un-featured file system) then I would recommend having a root partition and a home partition. Generally, 30-40MB for root and the remainder for home.

To explain the above a bit;

BTRFS segregates your home from root by using subvolumes. These subvolumes are independent from one another but share all the free space in the file system, thus one file system using all the space is the preferred set up. These subvolumes can easily have snapshots taken and "sent" (copied) to another BTRFS file system as a backup.

EXT4 does not separate your home from root by default, thus a separate partition for home is common. It certainly isn't required, but it makes some things easier, like re-installing Kubuntu from scratch if you break it (which most new users do more than once - all of us have) without having to backup your home folder first.

Generally, EXT4 is a bit faster than BTRFS but if you're using an SSD or NVME drive you won't notice the difference.

One other difference between the two is with BTRFS the swap file has to have special settings to exist on BTRFS where with EXT4 no special settings are required. The installer will create the initial swap file correctly but if you decide to change it later using BTRFS you will have to take the one extra step of setting "NODATACOW" on the swap file. It's easily done and well documented with How-Tos.

FYI, I filed a bug on Calamares (the installer) re. the 300MB message. Too many people have complained about it at this point - me included.

[jhoni146]

Everything is much clearer to me, thank you very much for your help! a pleasure.

[oshunluvr]

Glad I helped a bit. I hope your install goes as planned.

Welcome to the world of Linux and welcome to the Kubuntu Forum!

[jhoni146]

Hello again, I just installed Kubuntu, ignoring the 300MB warning for EFI, but when I finish and reinstall I see that grub has not been installed to choose which OS to start with, it automatically enters Windows.

[oshunluvr]

Some computers control EFI booting from BIOS. If this is the case, set it to boot to "Ubuntu" and then you should see the GRUB menu.

If you look in the EFI folder, is "Ubuntu" in there along with Windows?

[jhoni146]

If inside efi there are 3 folders: Boot, Microsoft, Ubuntu.

Until recently I had Ubuntu with Windows and Grub didn't fail me. I say this because of the bios issue, it should be fine because it worked in Ubuntu.

[jhoni146]

Although I think that the Ubuntu folder in EFI is not from now, but rather the old Ubuntu because the modification date is old.

The Ubuntu folder is probably not correct, because I think it is the old one and may have errors.


EDIT:

I edit the topic to inform that within the efi/ubuntu folder the date is today, also try to install grub from live cd with boot-repair but it still goes directly to windows.

[jhoni146]

Indeed the error was in the UEFI boot, I changed it from Windows to Ubuntu and the grub appears, thank you very much again for your help.

[jhoni146]

Now after the first reboot after booting, it no longer enters Kubuntu... when you select it as boot it goes black..., I'm losing the desire to install Linux...


As additional information, it goes black as soon as you press Ubuntu in grub, it does nothing else.

[jhoni146]

I have managed to start by removing (quiet splash) Change line: GRUB_CMDLINE_LINUX_DEFAULT='quiet splash', I don't know how it affects me other than that I see all the letters loading before starting.

[oshunluvr]

Is it loading after removing "quiet spash" ?