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The kernel is the bridge amongst program and hardware, and it is element of an working program that interacts with the hardware.

In ordinary situation, the number of installed kernels does not affect the system’s efficiency, but it is nonetheless proposed to get rid of aged unused kernels as it frees up room. Before we begin eradicating outdated unused kernels, it is crucial to notice that you need to constantly have at the very least two kernels on your technique at any time.

Eliminate Outdated Kernels

It is suggested to update the total system’s packages and energetic kernel right before getting rid of the previous kernels. To do so, execute the command:

Following updating, to examine the recent kernel staying employed, use the adhering to command:

To checklist all the kernels set up in your technique, use the command specified beneath:


As you can see, I have three Kernels mounted on my CentOS 8 program.

Now we will explore how to remove old inactive kernels from our programs.

As outlined over, you really should by no means take away all of the aged inactive kernels and must constantly have at minimum two kernels (1 lively – 1 inactive) in your technique.

Remove Outdated Kernels utilizing DNF Command

We can use the DNF command to take away aged unused kernels. Basically execute the “dnf remove” command with the :

$ sudo dnf eliminate –oldinstallonly –setopt installonly_limit=2 kernel

As you can see in the screenshot hooked up earlier mentioned, the terminal is inquiring to take away a few deals. Let the removal by urgent “y” and hitting “Enter”:

After profitable removal of the more mature kernel, if we execute the “rpm -q kernel” command again:

You can witness, we have only two kernels left.

If you have more than two kernels mounted, the command offered higher than will depart two kernels put in on your program and uninstall all other more mature and unused Kernel variations.

You can transform the range by providing a unique value to –setopt installonly_restrict=2.

In the command previously mentioned, the –setopt is used to modify the default benefit from /etcetera/dnf/dnf.conf. If you never command a price, then dnf will acquire the default worth from dnf.conf.

This command will only function in circumstance the most current kernel is lively. If an more mature edition is functional, the command will unsuccessfully attempt to get rid of it.

One more approach functions on more mature variations of CentOS, but with the launch of CentOS 8, this system has stopped doing work.

So, if you’re nonetheless making use of an more mature variation of CentOS/RHEL, you can still use the command offered under to remove old kernels:

$ sudo offer-cleanup –oldkernels –count=2

The command supplied over will go away two kernels put in and uninstall all other more mature and unused Kernel variations on your older variation of the CentOS/RHEL method.


This short article gives an intensive tutorial on how to clear away previous and unused kernels from CentOS 8. We also talked about some superior tactics to hold in intellect whilst taking away inactive kernels.

We acquired two distinct techniques we can use to take away outdated and unused kernels from our technique. One particular of these methods has turn out to be obsolete on newer variations of CentOS working programs but can continue to arrive in useful if you are using an older model of CentOS.

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