How to Downgrade the Kernel if a New One Breaks the System on Arch Linux

Arch Linux is known for being a bleeding-edge rolling-release distribution, which means users often get the latest software updates shortly after they’re released. This includes the Linux kernel, which is frequently updated with performance improvements, new hardware support, and security patches. However, with this level of freshness comes a certain degree of risk—occasionally, a new kernel version might introduce regressions or break your system altogether.

When such issues arise, knowing how to downgrade your Linux kernel becomes an essential skill. In this article, we’ll walk you through multiple approaches to downgrade your kernel safely and effectively on Arch Linux.

Why Downgrade the Kernel?

There are several reasons you might need to roll back to a previous kernel version:

• System won’t boot properly after a kernel update.
• Hardware issues, such as broken Wi-Fi, GPU drivers, or peripherals no longer functioning.
• Kernel panics or stability issues introduced with the latest update.
• Compatibility problems with third-party modules or proprietary drivers like NVIDIA.

Downgrading isn’t something you want to do lightly, but it’s sometimes necessary to keep your system functional until the issue is resolved upstream.

Step 1: Identify the Problem

Before downgrading, it’s important to confirm that the issue is actually caused by the kernel update. If the system still boots, you can use the following command to check your current kernel version:

uname -r

Compare this with the version installed previously (if known), or check your Pacman log to see when the kernel was upgraded:

cat /var/log/pacman.log | grep linux

This can show you exactly when the kernel was updated and which version was installed.

Step 2: Boot into an Older Kernel (if available)

If you have the linux-lts (Long Term Support) kernel or any previous kernel installed, you might still be able to boot your system using those.

1. Reboot your system.
2. At the GRUB menu, press Esc or hold Shift during boot to access the menu.
3. Select Advanced options for Arch Linux.
4. Choose the older kernel version (if available).

If the system boots fine with the older kernel, then you have a working environment from which to downgrade or fix the broken one.

If you can’t boot at all, you’ll need to use a live USB to chroot into your system (covered in Step 6).

Step 3: Downgrade the Kernel Using the Pacman Cache

Pacman, the Arch package manager, retains cached versions of packages in /var/cache/pacman/pkg/. If the kernel was recently updated, you can often find the older version here.

1. Check what kernel versions are available in the cache

ls /var/cache/pacman/pkg/ | grep linux

Look for files like:

• linux-6.7.4.arch1-1-x86_64.pkg.tar.zst
• linux-headers-6.7.4.arch1-1-x86_64.pkg.tar.zst

2. Downgrade the kernel and headers

sudo pacman -U /var/cache/pacman/pkg/linux-6.7.4.arch1-1-x86_64.pkg.tar.zst
sudo pacman -U /var/cache/pacman/pkg/linux-headers-6.7.4.arch1-1-x86_64.pkg.tar.zst

⚠️ Make sure the versions of linux and linux-headers match exactly.

3. Prevent automatic updates (temporarily)

After downgrading, you should prevent the kernel from being updated automatically during system upgrades.

Edit /etc/pacman.conf:

sudo nano /etc/pacman.conf

Under the [options] section, add:

IgnorePkg = linux linux-headers

Remember to remove this line once the issue is resolved, so you don’t miss critical kernel updates in the future.

Step 4: Install an Older Kernel Using the Arch Archive (Downgrade Tool)

If the version you want is not in your Pacman cache, you can use the downgrade utility to fetch and install older versions from the Arch Archive.

1. Install the downgrade tool

yay -S downgrade

Or if you prefer manually using the archive, you can download packages from: https://archive.archlinux.org/packages

2. Run the downgrade command

sudo downgrade linux

You’ll be presented with a list of available versions. Choose the version that was working for you and confirm.

Repeat for linux-headers:

sudo downgrade linux-headers

The tool will offer to add the kernel to IgnorePkg automatically.

Step 5: Regenerate GRUB and Initramfs (if needed)

After downgrading, it’s a good idea to regenerate your initramfs and update the GRUB configuration to make sure everything boots correctly.

Regenerate initramfs

sudo mkinitcpio -P

Regenerate GRUB config (if necessary)

sudo grub-mkconfig -o /boot/grub/grub.cfg

Reboot and select the downgraded kernel from the GRUB menu.

Step 6: Use Arch ISO (Live USB) to Downgrade from a Broken System

If your system doesn’t boot at all, you can use the Arch ISO to chroot into your installed system and downgrade the kernel from there.

1. Boot from Arch Linux ISO (Live USB)

2. Mount your root partition

mount /dev/sdXn /mnt

Replace /dev/sdXn with your actual root partition.

If you have a separate boot or EFI partition:

mount /dev/sdXn /mnt/boot
mount /dev/sdXn /mnt/boot/efi

3. Mount essential virtual filesystems

mount -t proc /proc /mnt/proc
mount --rbind /sys /mnt/sys
mount --rbind /dev /mnt/dev
mount --make-rslave /mnt/sys
mount --make-rslave /mnt/dev

4. Chroot into the system

chroot /mnt /bin/bash

5. Downgrade as described in Step 3 or Step 4

After downgrading, exit chroot, reboot, and your system should boot normally with the older kernel.

Step 7: Install the linux-lts Kernel as a Backup

One smart preventative step is to always have a fallback kernel like linux-lts installed alongside the regular one.

Install LTS kernel

sudo pacman -S linux-lts linux-lts-headers

This kernel receives fewer updates and is maintained for long-term stability. GRUB will automatically add it to the boot menu, and it can be a life-saver if a newer mainline kernel breaks your system.

Best Practices to Avoid Kernel Issues

• Keep the linux-lts kernel installed at all times.
• Regularly back up your system (especially /boot, /etc, and your home directory).
• Use IgnorePkg sparingly—only to delay an update until it’s fixed upstream.
• Monitor Arch Linux news ( https://archlinux.org/news) before doing full system upgrades. Some updates require manual intervention.
• Consider using Timeshift (with BTRFS or rsync) to take snapshots before updates.

Conclusion

While kernel issues are rare on Arch Linux, the rapid pace of development can sometimes introduce regressions. Downgrading the kernel is a safe and manageable way to get your system running again, especially when paired with smart practices like keeping the linux-lts kernel installed and monitoring updates.

With the right tools—Pacman cache, downgrade, and even chroot recovery—you’re never far from restoring stability. Arch empowers users with full control over their system, and with that power comes the need to understand how to handle situations like these. Thankfully, as you’ve seen, it’s all very doable with a bit of preparation and knowledge.