(Please provide enough information to help the Debian
maintainers evaluate the report efficiently - e.g., by filling
in the sections below.)

Boot method: USB
Image version: https://cdimage.debian.org/debian-cd/current/amd64/iso-
cd/debian-13.2.0-amd64-netinst.iso
Date: 31/12/2025

Machine: Huawei Notebook
Partitions: <df -Tl will do; the raw partition table is preferred>


Base System Installation Checklist:
[O] = OK, [E] = Error (please elaborate below), [ ] = didn't try it

Initial boot:           [O]
Detect network card:    [O]
Configure network:      [O]
Detect media:           [O]
Load installer modules: [O]
Clock/timezone setup:   [O]
User/password setup:    [O]
Detect hard drives:     [O]
Partition hard drives:  [E]
Install base system:    [O]
Install tasks:          [O]
Install boot loader:    [O]
Overall install:        [E]

Comments/Problems:

I ran the debian 13.2 installation on my machine, with something like 55 GB
free space (Windows and data got the rest of the disk).

I chose guided partitioning of the contiguous free space, with root (/) and
/home in different partitions, so the installer assigned 10 GB to the root (/)
partition and the rest of the contiguous available space to the /home.
Installation continued by installing the base system and when installing
programs I added KDE environment and web server to the initial chosen software
to install. The installation got stuck at some point, leaving no option other
than exit the installation and without any comment on what had failed.

After that I retried the installation in text mode and without choosing KDE
environment or web server, just standard tools and GNOME. It went well. Once
logged in I installed KDE and was then that I ran out of space in root
partition.

Third try (I didn't want to boot from a liveUSB to redo the partitioning), I
ran again the installation, this time with manual partition so I assigned 20 Gb
to root partition, and created a separated /var and /home partition.

So, the thing is that:
 1 - 10 GB seems not to be enough space for root partition if a user is
installing aditional software.
 2 - This is not mentioned in the Installation Guide (or I haven't been able to
find it)
 3 - If the user chooses the option of guided installation with / and /home
separated, the installation system will assign 10 GB of space to the root
partition, without asking otherwise.
 4 - Once assigned, and in order to change the allocated space, if the user
wants to change it (which was my case), the only way to do it is by manual
partitioning of the disk.

Some improvements for this "failure" during the installation would be:

- Improve the Installation Guide to suggest more than 10 GB of space in root
partition in case additional SW is installed (would be nice to say this in
section 6.3.4. Partitioning and Mount Point Selection, rather than do it in the
Anex C).

- Give the option during the guided partitioning to change the "default" 10 GB
assigned to root partition

- If the installation crashes because of lack of space during the installation
of programs, would be nice that the user is aware of this situation (I got no
clue of what was causing the installation to crash).

I guess it depends on which additional software you install. AFAICS 10GB
should be more than enough to install any single desktop environment:
the base system takes ~1GB, KDE takes ~5.5GB, GNOME takes 3.6GB, the web
server task takes only ~100MB. It is not clear whether you selected only
KDE + web server or GNOME + KDE + web server, but even the latter take
~6.6GB and should fit in 10GB.

Did you check the disk usage after both installation failures ? The last
times I saw a kind of "no disk space" error during installation, it was
caused by error messages flooding system logs and filling /var/log.

This is true with 55GB available disk space. It depends on available
disk space. With Trixie, the size of the / partition for guided
partitioning with separate /home is 7.5GB + ~5% of remaining available
disk space (after subtracting minimum sizes of all partitions) up to
100GB. During the discussion 7.5GB was considered enough for any desktop
environment. Maybe the 5% ratio is too low and should be increased. With
previous versions, the size of the / partition would have been 20GB.

Hi Rodrigo,

First of all let me say Thank You for this very detailed and rational bugreport!

Rodrigo <rodrigo.irurzun@gmail.com> wrote (Thu, 01 Jan 2026 18:31:51 +0100):

Depending on the use case the user intends for his machine, 55G of free disk
space might be much or very low.
So, the automatic partition recipes are always an compromise: on a server, you
need much space for partitions like /srv, on a workstation you need space on
the root and maybe home partition, and so on.
We have different recipes for guided partitioning to fit these requirements, but
we often receive reports, where users see different assumptions etc.

Overall, 55G of disk space is not that much these days for the OS and user space,
if you want to use a generic setup (aka no manual partitioning).
We cannot know what you want to do with KDE. Do you need much space on /home for
editing videos?

Coming back to your 10G root partition: that value is not static, but it depends
on the size of your harddisk/the size of the available free space on your harddisk.

A bigger harddisk like 128G or 256G would get a much bigger root partition.

Maybe we could improve this, yes.

Yes, it's true, that's the chose between Guided and Manual partitioning.
You cannot choose the first one, and then at the same time expect to get the
latter (at least partman currently is not smart enough for such concept).

ACK.

As stated above, that "10G for root" is not a default, it depends on the
overall disk size.

This has been mentioned several times, yes!
Sorry, that this is still an issue!


Holger