Hey, no worries, this is a very common confusion for beginners. The root partition (/) is indeed meant for system files, but it doesn’t automatically “reserve” all your remaining free space unless you explicitly tell the installer to use it that way. Most installers assume you’ll create other partitions (like swap or BIOS/UEFI partitions) first, or at least guide you to allocate the remaining space manually.

Since you still have a large chunk of unallocated space, you can usually fix this without reinstalling by creating a new partition in that free space or resizing your existing partitions using a tool like GParted. Just make sure not to touch your root partition if it already contains the system, you don’t want to accidentally lose data.

If you want, I can write a quick step-by-step on how to safely use that unallocated space without reinstalling.

I thought the root partition for “system files” meant just that, not that it would take up essentially all remaining free space. It never occurred to me that I also needed to explicitly create a partition for the rest of the free space, and the installer didn’t warn me about this either. I was installing the system on a separate SSD.

I’m asking on Reddit now what to do and whether I can fix this without reinstalling. But in my opinion, things like this should be clearly explained for beginners like me. Also, creating such a large root partition before setting up swap and bios_grub (or whatever is required) probably isn’t ideal or at least there should be a clear mention of what happens to unallocated free space.

Thank you again Ravi!!!
I will try and let you know
Nick

Hi Nick, great question!

No. 3 should be done during the partitioning step of the Linux installation process.
No. 4 is applied after installation, during the first boot.
No. 5 is optional and can be done at any time if needed.

Hope this helps! Let me know if you have more questions.

How and when to apply Nos 3, 4 and 5?
During the Linux installation or Separately before the beginning of installation?
Thank you very much again,
Nick