Technical Tip: How to safely perform /boot cleanup

Pre-requisites.

1. Verify the running kernel version:

uname -sr

Example output: Linux 4.18.0-513.11.1.el8_9.x86_64.

2. List installed kernel packages:

rpm -q kernel

Example output:

kernel-4.18.0-513.9.1.el8_9.x86_64
kernel-4.18.0-513.11.1.el8_9.x86_64
kernel-4.18.0-513.24.1.el8_9.x86_64

3. Take a snapshot of the VM before proceeding with the cleanup steps. It is a must.

Cleanup Steps.

Remove older kernel versions.
Use the following command to remove older kernels, keeping only the latest two:

yum remove $(yum repoquery --installonly --latest-limit=-2 -q)

Important Note:
Before confirming the removal, verify that the output includes all three components of the same kernel version:

• Kernel.
• Kernel-core.
• Kernel-modules.

Example output:

Removing:
kernel x86_64 4.18.0-513.9.1.el8_9 @baseos
kernel-core x86_64 4.18.0-513.9.1.el8_9 @baseos
kernel-modules x86_64 4.18.0-513.9.1.el8_9 @baseos

If the versions match and are not the currently running kernel, press y to confirm.

Post-Cleanup Verification.

1. Recheck installed kernels:

rpm -q kernel

2. Ensure the current kernel is still installed:

uname -r

3. Reboot to verify system stability:

reboot