Debian 10 Live Installer - Bypass Calamares installer 10 GB requirement

Calamares installer minimum disk size requirement

Debian 10.7 has got a new graphical installer, the Calamares installer.

This installer does however have something similar to the Windows 10 installer - an overprotective limit or requirement.

In this case a minimum 10 GB available space requirement to allow installation, the real size required for the installer to write the files to the system partition excluding EFI and swap partitions on MATE is about 7,5 GB during the install and 7,1 GB afterwards.

Note that the Calamares installer on the Debian Live ISO installs some packages you may not want by default, like Firefox, GIMP and LibreOffice. Removing these (apt purge firefox* gimp* libreoffice*) reduces the used space to 5 GB. It does not install OpenSSH server (apt install openssh-server).

If you are looking for a mimimal install you might use the Debian network install from a minimal CD instead, https://www.debian.org/CD/netinst/.

Bypass the size requirement

Let's bypass the requirement in the live installer anyways. Open a terminal, go sudo:
sudo bash

Open the welcome module settings for Calamares in Pluma if you run MATE:
pluma /etc/calamares/modules/welcome.conf
Or in vi:
vi /etc/calamares/modules/welcome.conf

Edit this line:
	requiredStorage:	10

To this:
	requiredStorage:	1

Save the file, then run the installer - click on the icon on the desktop or run calamares.

Skip or reduce the swap

During the partitioning in Calamares you will be requested to either do a manual partitioning or an automatic one.

Doing an automatic on a 10 GB disk or smaller will not work, because the installer makes up an unnecessary swap of 3,1 GB or less and then it fills up the system partition and the installer crashes.

So, do a manual partitioning. If you have enough RAM skip the swap partition.

For a legacy BIOS/MBR installation you can simply make one big EXT4 partition and mount / on it.

For an UEFI/GPT installation it gets more complicated, you could do a FAT16 partition of 300 MB, set the type to EFI System and mount /boot/efi on it and then the rest as one big EXT4 partition and mount / on it.