To display the current version of Linux (kernel) running on your system, run this command.
# uname -sr
Linux 3.10.0-327.10.1.el7.x86_64

You can list all kernel images installed on your system like this.
# rpm -q kernel
kernel-3.10.0-229.el7.x86_64
kernel-3.10.0-229.14.1.el7.x86_64
kernel-3.10.0-327.3.1.el7.x86_64
kernel-3.10.0-327.10.1.el7.x86_64

You need to install yum-utils, which is an assortment of utilities that integrate with yum to make it more powerful and easier to use, by extending its original features in several different ways.
# yum install yum-utils

One of these utilities is package-cleanup which you can use to delete old kernel as shown below, the count flag is used to specify the number of kernels you want to leave on the system.
# package-cleanup --oldkernels --count=2

Removing Old Kernels
Loaded plugins: fastestmirror, langpacks, product-id, versionlock
-→ Running transaction check
—> Package kernel.x86_64 0:3.10.0-229.el7 will be erased
—> Package kernel.x86_64 0:3.10.0-229.14.1.el7 will be erased
—> Package kernel-devel.x86_64 0:3.10.0-229.1.2.el7 will be erased
—> Package kernel-devel.x86_64 0:3.10.0-229.14.1.el7 will be erased
-→ Finished Dependency Resolution
Dependencies Resolved
===============================================================================================================================================================================================
Package                                       Arch                                    Version                                                Repository                                  Size
===============================================================================================================================================================================================
Removing:
kernel                                        x86_64                                  3.10.0-229.el7                                         @anaconda                                  131 M
kernel                                        x86_64                                  3.10.0-229.14.1.el7                                    @updates                                   131 M
kernel-devel                                  x86_64                                  3.10.0-229.1.2.el7                                     @updates                                    32 M
kernel-devel                                  x86_64                                  3.10.0-229.14.1.el7                                    @updates                                    32 M
Transaction Summary
===============================================================================================================================================================================================
Remove  4 Packages
Installed size: 326 M
Is this ok [y/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Erasing    : kernel-devel.x86_64                            1/4 
Erasing    : kernel.x86_64                                  2/4 
Erasing    : kernel-devel.x86_64                            3/4 
Erasing    : kernel.x86_64                                  4/4 
Loading mirror speeds from cached hostfile
* base: centos.mirror.snu.edu.in
* epel: repo.ugm.ac.id
* extras: centos.mirror.snu.edu.in
* rpmforge: kartolo.sby.datautama.net.id
* updates: centos.mirror.snu.edu.in
Verifying  : kernel-3.10.0-229.el7.x86_64                   1/4 
Verifying  : kernel-devel-3.10.0-229.14.1.el7.x86_64        2/4 
Verifying  : kernel-3.10.0-229.14.1.el7.x86_64              3/4 
Verifying  : kernel-devel-3.10.0-229.1.2.el7.x86_64         4/4 
Removed:
kernel.x86_64 0:3.10.0-229.el7           kernel.x86_64 0:3.10.0-229.14.1.el7           kernel-devel.x86_64 0:3.10.0-229.1.2.el7           kernel-devel.x86_64 0:3.10.0-229.14.1.el7          
Complete!

Important: After running the above command, it will remove all old/unused kernels and keep the current running and old latest kernel as backup.
Topic revision: r1 - 21 Jun 2018, Dibiase
This site is powered by FoswikiCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding Wiki_Virgo_LSC? Send feedback