[Bug] No filesystem could mount root #5349
Description
Describe the bug
[Author TODO: A clear and concise description of what the bug is.]
When using the tutorial at https://github.com/firecracker-microvm/firecracker/blob/main/docs/getting-started.md, the rootfs will not mount when booting the VM. Errors on boot are:
[ 0.961380] No filesystem could mount root, tried:
[ 0.961380] ext3
[ 0.962433] ext2
[ 0.962792] ext4
[ 0.963133] squashfs
[ 0.963516] xfs
[ 0.963901]
[ 0.964487] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(254,0)
Is there a better rootfs to use?
To Reproduce
[Author TODO: Steps to reproduce the behaviour:]
Follow the tutorial, boot the VM, rootfs fails to mount
Expected behaviour
[Author TODO: A clear and concise description of what you expected to happen.]
Follow the tutorial, boot the VM, rootfs mounts
Environment
[Author TODO: Please supply the following information):]
- Firecracker version: v1.12.1
- Host and guest kernel versions:
- $ sudo lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 24.04.3 LTS
Release: 24.04
Codename: noble
$ uname -a
Linux firecracker-kvm 6.14.0-27-generic #27~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Jul 22 17:38:49 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
- Rootfs used:
Download a rootfs
wget -O ubuntu-$ubuntu_version.squashfs.upstream "https://s3.amazonaws.com/spec.ccfc.min/$latest_ubuntu_key"
Create an ssh key for the rootfs
unsquashfs ubuntu-$ubuntu_version.squashfs.upstream
ssh-keygen -f id_rsa -N ""
cp -v id_rsa.pub squashfs-root/root/.ssh/authorized_keys
mv -v id_rsa ./ubuntu-$ubuntu_version.id_rsa
create ext4 filesystem image
sudo chown -R root:root squashfs-root
truncate -s 400M ubuntu-$ubuntu_version.ext4
sudo mkfs.ext4 -d squashfs-root -F ubuntu-$ubuntu_version.ext4
- Architecture: x86_64
- Any other relevant software versions:
Additional context
[Author TODO: How has this bug affected you?]
[Author TODO: What are you trying to achieve?]
[Author TODO: Do you have any idea of what the solution might be?]
Checks
- Have you searched the Firecracker Issues database for similar problems?
- Have you read the existing relevant Firecracker documentation?
- Are you certain the bug being reported is a Firecracker issue?