Issues with Virtualbox

[Snowhog]

I'm having a terrible time getting any VM installation to successfully boot after installation.

I'm using Virtualbox from the repositories. The host is Kubuntu 24.04.2 LTS. Packages virtualbox (7.0.16-dfsg-2ubuntu1.1), virtualbox-dkms (7.0.16-dfsg-2ubuntu1.1), virtualbox-qt (7.0.16-dfsg-2ubuntu1.1) and virtualbox-guest-additions-iso were installed.

I started Virtualbox and created a new VM for Kubuntu 25.04. The VM settings are as I've always used:


I started the VM and chose to install Kubuntu. I specified a new, GPT partition table, creating an 8 MB unformatted partition with the bios-grub flag set, and the rest of the drive partitioned as btrfs with a mount point of /. The install went off without any issues. When restarting the VM however, it fails to boot:


What is going on? This has been an issue for me for months now.

[claydoh]

Make sure the machine is set to use UEFI firmware

Skip the 8mb, or at least don't bother setting the flag. But really just skip it. It's only needed with mbr setups on gpt partition schemes , I believe.

You will need an efi partition flagged as boot and mounted at /boot/efi. It can be small ~100mb. Calamares will gripe but you ignore it and proceed.

I think you can use mbr and BIOS for your purposes instead of gpt, but I'm not sure if you will need that 8mb slack space. BIOS and gpt seem to be a pita

Not hawking Virt Manager, but I use uefi and gpt, and just add efi and btrfs partitions, set a flag and mount points and go...

In any case
If the empty space is needed calamares will create it I think.