How to downgrade the Ubuntu kernel
It is always a good idea to update the kernel in Ubuntu. Why? New kernel updates mean more recent drivers, bug fixes, etc. However, sometimes kernel updates break things. If you’ve had something break, you may want to downgrade the kernel. Here’s how.
Ubuntu Mainline Kernel Installer
Ubuntu Mainline Kernel Installer continues the now-abandoned Ubuntu Kernel Upgrade Utility (Ukuu). It can automatically fetch the latest Ubuntu kernel packages, install them, and notify you of new versions.
Ubuntu Mainline Kernel Installer isn’t just for new kernels, though. Users can also use it to downgrade the Ubuntu kernel to older versions. Here’s how to use the app.
Installing Ubuntu Mainline Kernel Installer
You must install the Ubuntu Mainline Kernel Installer application on your Ubuntu system. The app is easy to get working as the developer provides an easy to set up PPA.
To get the PPA working for Ubuntu Mainline Kernel Installer, launch a terminal window. You can launch a terminal window by pressing Ctrl + Alt + T on the keyboard or launching it from the app menu.
With the terminal window open and ready to use, run the add-apt-repository command to add the UMKI PPA to your Ubuntu system.
sudo add-apt-repository ppa:cappelikan/ppa
Once you have added the PPA to your Ubuntu system, you must run the update command to refresh Ubuntu’s software sources.
sudo apt update
Finally, you can install UMKI on Ubuntu with the apt install command when everything is up to date.
sudo apt install mainline
Downgrading with Ubuntu Mainline Kernel Installer
To downgrade the Ubuntu kernel with UMKI, launch the app and follow the step-by-step instructions below.
Step 1: Look through the list of available kernels in UMKI. Scroll through and find an older kernel to downgrade from the version of the Linux kernel you are running at the moment.
For example, to downgrade 5.13, you might select 5.12 or newer.
Step 2: Select the kernel you wish to downgrade to and select it with the mouse. Once you’ve chosen it, click on the “Install” button. Selecting this button will download the kernel and install it on your computer. This process should take a bit.
Step 3: When you’ve finished installing the kernel, reboot. Then, on the Grub boot screen, choose “Advanced Options for Ubuntu” and load the downgraded kernel.
Step 4: After loading up the older kernel, re-launch the Ubuntu Mainline Kernel Installer app and select the newer kernel you have installed. Then, select the “Uninstall” command to get rid of it.
Once your newer kernel is removed, you’ll have successfully downgraded the Ubuntu kernel.
Installing older kernels with Ukuu
Another way Ubuntu users can downgrade the Ubuntu kernel is with the Ukuu app. Ukuu is a kernel installation tool, and although it is no longer maintained, it is still a helpful program and can fetch kernels from the Ubuntu development website.
Installing Ukuu on Ubuntu
Before using Ukuu to downgrade the Ubuntu kernel, you’ll have to install the app on your computer. Unfortunately, as the app has been abandoned, the developer no longer maintains a PPA for Ukuu. Thankfully, there’s an executable program that you can download and run to get Ukuu.
To get your hands on Ukuu, open up a terminal window on the Ubuntu desktop. You can open one by pressing Ctrl + Alt + T on the keyboard. Or by searching for “Terminal” in the app menu.
With the terminal window open, use the wget download command to download the latest release of Ukuu to your Ubuntu system.
wget https://github.com/teejee2008/ukuu/releases/download/v18.9.1/ukuu-v18.9.1-amd64.run
After downloading the Ukuu executable file, you must update its permissions. Using the chmod command, mark the file as executable.
chmod +x ukuu-v18.9.1-amd64.run
Install the program on your Ubuntu system by running the following command.
./ukuu-v18.9.1-amd64.run
Downgrading with Ukuu
To downgrade the Ubuntu kernel with Ukuu, follow the step-by-step instructions below.
Step 1: Open up Ukuu by searching for it in the app menu. Once it is open, scroll through the list of available kernels and select the older one you wish to install.
Step 2: After selecting an older kernel, find the “Install” button and click on it with the mouse. Clicking on this button will install the selected kernel to Ubuntu.
Step 3: Once you’ve installed an older version of the Ubuntu kernel, reboot. Then, in Grub, select the older kernel. You may need to select “Advanced options for Ubuntu” to locate the older kernel.
Step 4: Upon loading Ubuntu back up with the older kernel, re-launch Ukuu. Then, locate the newer kernel (the one Ubuntu comes with) and select it with the mouse. Finally, click “Remove” to uninstall it.
When you uninstall the newer kernel, you’ll have downgraded the kernel in Ubuntu.
