Unknown filesystem type '[type]'

[Niklan]

Which ISO version are you using?

2025-01-01

The installation log

Sorry, I don't have one with an error. But I think it's easily reproducible, so I'll explain it.

describe the problem

Description of the issue

The bug I encountered, I think, is very easy to reproduce. For the first time, I installed Arch via Archinstall. So, when I booted the system, I ran pacman -Syuu and then archinstall, and the uu flag was the problem. This updated the Linux kernel, which was an issue with Archinstall.

I selected what I wanted to install, in particular, the Btrfs file system with all its defaults (no subvolumes, compression enabled etc.). Then I ran the installation, waited for 5 seconds for the drive to be formatted or whatever else it was supposed to do, and then I instantly got an error message.

mount: /mnt/arch_btrfs: unknown filesystem type 'btrfs'.

After a little research, I found out that this was most likely caused by a Linux kernel update and the modprobe command did not have relevant information or anything like that. To solve this, you need to reboot the system, but since it's a live USB with the kernel in RAM, there's no way to do that after the update has been made.

Then I rebooted and tried it with pacman -Sy archlinux-keyring and archinstall, but it immediately failed on the archinstall call.

Sorry for the poor photo quality. I didn't expect to use them to report a problem.

Basically, it formatted the disk and failed to create a BTRFS file system. This broke the partitions on the drive, so I fixed it by using the dd command to overwrite the first gigabyte of the drive with zeros (dd if=/dev/zero of=/dev/nvme0n1), and then running archinstall again. The installation worked fine, but I didn't update the Linux kernel this time.

Steps to reproduce

1. Boot into arch ISO
2. pacman -Syuu - there must be a kernel update I think for bug to be reproduced
3. pacman -Sy archlinux-keyring archinstall
4. Run archinstall and selected whatever you want
5. Run "Install"
6. It will fail after 5 second countdown

Proposed solution

I think it is better to have some kind of protection in place for such situations. Since the system can't find the btrfs filesystem type, it may be possible to detect and alert the user that there is a problem and, most likely, an updated kernel should be avoided. A bug by itself isn't a big deal, but a corrupted partition after that is a problem.

[svartkanin]

Not sure if this can be classified as a archinstall bug, as you said running pacman with uu will require a reboot. So if you only run a regular archinstall package upgrade everything should work as expected.

We can handle the broken filesystem potentially in a better way and try to reformat it