[Pre-Install] Manual partitioning advice for multiboot with Kubuntu 26.04LTS and two more OSs.

[zahtar]

Hello everyone! Happy new LTS release! 🎂🥳

I am thinking of installing kubuntu 26.04 on my laptop, as well as Vanilla OS 2 Orchid, along with the existing win11. I would like to ask for partitioning advice prior installation.

I have installed a 1TB m2 drive to the laptop, cloned the old drive´s partitions with clonezilla and now I have plenty of unallocated space left, around 800GB I think. The windows partitions take up less than 200GB and I am not planning to store data or install any software there.

My current wish is to be able to run all operating systems on my laptop, and hopefully be able to upgrade to kubuntu 28.04 LTS without the system breaking in about two years.

A blog in the vanilla OS website suggests the following for manual partitioning:

• GPT table
• 1GB for /Boot (ext4)
• 512MB for /EFI (fat32)
• 20.5GB ¨for the Root partition pool unformatted.¨, which I do not understand what it means,
• swap for hibernation support
• remaining storage for /var (btrfs)

I do not know whether the author supposed a dedicated drive, but my in-use drive already has a gpt table if I am not mistaken, so it seems I am hopefully ok with that one.

I had a chat with an AI tool which gave me the below suggestion:

• leave everything windows related as-is
• 80GB for Kubuntu root (ext4 or btrfs), mount point /
• 80GB for Orchid root (ext4 or btrfs), mount point /
• 24GB linux swap, shared between Kubuntu and Vanilla
• remaining GB for storage, accessible via all three operating systems. (ntfs)
• install Vanilla, then Kubuntu so I keep the Kubuntu boot loader.
• ¨Use the existing ESP for all bootloaders; do not create a new ESP.¨
• ¨Add the NTFS partition to each OS /etc/fstab using UUID: sudo blkid to get UUID, then mount with ntfs-3g options for Linux.¨

So, my question is, do the above make sense? Is there by chance a different recommended method for manually partitioning before installing multi boot with 2 linux distros + windows?

Thank you in advance!


References:

• https://vanillaos.org/blog/article/2...-devlog-22-nov
• chat gpt5-mini output, on 25 Apr 2026

[INVICTRA]

Yes that looks OK. Should work. Follow AI suggestion.
After you got everything installed then make a backup of the boot partition (ESP) with something like KDE Partition Manager. Because Windows might delete it and recreate it in certain scenarios (Big update, FIX boot etc.). I find it faster to just restore a ESP that windows ****ed up than using live CD to repair Linux boot.

[jlittle]

• install Vanilla, then Kubuntu so I keep the Kubuntu boot loader.

(You'll want to turn on grub's OS prober, by setting GRUB_DISABLE_OS_PROBER=false in /etc/default/grub and running update-grub.)

Some Vanilla update might still trample on the kubuntu boot loader. If Vanilla uses grub, you could uninstall it from Vanilla to stop that. Being familiar with sudo efibootmgr could be useful.

I don't know how Vanilla installs to a btrfs; if it uses subvolumes you could put it and Kubuntu in the same btrfs to economize on space, with some /etc/fstab and grub manipulation.