Troubleshooting Kernel Panic: VFS Unable to Mount rootfs Unknown-Block (2,0) on Ubuntu 22.04

Troubleshooting Kernel Panic: VFS Unable to Mount Rootfs Unknown-Block(2,0) on Ubuntu 22.04 VM Installed on Raspberry Pi 4 PXE Server

If you have installed Ubuntu 22.04 on a virtual machine (VM) using a Raspberry Pi 4 as a PXE server and are experiencing a kernel panic with the error message "VFS: Unable to mount rootfs on unknown-block(2,0)", this article is for you. We will cover the key concepts related to this issue and provide a detailed guide on how to troubleshoot and resolve it.

Understanding the Error Message

The error message "VFS: Unable to mount rootfs on unknown-block(2,0)" is a kernel panic error that occurs when the system is unable to mount the root file system. This can be caused by a number of issues, including incorrect disk partitioning, corrupt file systems, or missing device drivers.

Troubleshooting the Issue

To troubleshoot this issue, you will need to boot the VM in recovery mode and check the disk partitioning and file systems. Here are the steps to follow:

1. Boot the VM in recovery mode by selecting the "Advanced options for Ubuntu" option from the GRUB menu.
2. Select the recovery mode option and press Enter.
3. Select the "root" option and press Enter.
4. Run the following command to check the disk partitioning:
   sudo fdisk -l

   This will display a list of the disk partitions. Check if the root file system is correctly partitioned and has the correct file system type (ext4, xfs, etc.).

5. Run the following command to check the file systems:
   sudo fsck -A

   This will check all the file systems for errors and automatically repair them if possible. If any errors are found, you will be prompted to manually repair them.

6. If the file systems are clean, run the following command to mount the root file system:
   sudo mount /dev/sdXY /

   Replace "sdXY" with the correct disk partition for the root file system. For example, if the root file system is on /dev/sda1, the command would be:

   sudo mount /dev/sda1 /
7. Once the root file system is mounted, run the following command to start the system:
   sudo systemctl default

   This will start the system in normal mode.

Preventing the Issue

To prevent this issue from occurring in the future, make sure to properly partition the disk and format the file systems before installing the VM. You can also try using a different PXE server or updating the device drivers for the Raspberry Pi 4.

References

• Install Ubuntu Server
• PXE Network Booting
• Firmware for Raspberry Pi

This article covers the key concepts related to the "VFS: Unable to mount rootfs on unknown-block(2,0)" kernel panic error on Ubuntu 22.04 VM installed on a Raspberry Pi 4 PXE server. By following the troubleshooting steps provided, you should be able to resolve the issue and prevent it from occurring in the future. For more information, please refer to the references provided.

End of article.