CentOS - How to install kernel-debuginfo

First, check if you have the following this file (CentOS-Debuginfo.repo) in /etc/yum.repos.d

[root@abc yum.repos.d]# ls
CentOS-Base.repo  CentOS-Debuginfo.repo  CentOS-Media.repo

The content of CentOS-Debuginfo.repo is as shown below, from this file, we know the repo is debug (the name is enclosed with [ ]) and this repo is not enabled by default (enabled=0).

# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client.  You should use this for CentOS updates
# unless you are manually picking other mirrors.
#

# All debug packages from all the various CentOS-5 releases
# are merged into a single repo, split by BaseArch
#
# Note: packages in the debuginfo repo are currently not signed
#

[debug]
name=CentOS-6 - Debuginfo
baseurl=http://debuginfo.centos.org/6/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-Debug-6
enabled=0

To install kernel-debuginfo for your kernel, use yum as shown below

[root@abc yum.repos.d]# yum --enablerepo=debug install kernel-debuginfo-2.6.32-220.el6

If you omit kernel version, yum will pull the latest kernel-debuginfo file as shown below

[root@abc yum.repos.d]# yum --enablerepo=debug install kernel-debuginfo
Loaded plugins: fastestmirror, refresh-packagekit, security
Determining fastest mirrors
 * base: mirror.rndc.or.id
 * extras: kartolo.sby.datautama.net.id
 * updates: buaya.klas.or.id
base                                                     | 3.7 kB     00:00
debug                                                    | 1.9 kB     00:00
debug/primary_db                                         | 753 kB     00:19
extras                                                   | 3.5 kB     00:00
updates                                                  | 3.5 kB     00:00
updates/primary_db                                       | 1.5 MB     00:34
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package kernel-debuginfo.x86_64 0:2.6.32-358.2.1.el6.centos.plus will be installed
--> Processing Dependency: kernel-debuginfo-common-x86_64 = 2.6.32-358.2.1.el6.centos.plus for package: kernel-debuginfo-2.6.32-358.2.1.el6.centos.plus.x86_64
--> Running transaction check
---> Package kernel-debuginfo-common-x86_64.x86_64 0:2.6.32-358.2.1.el6.centos.plus will be installed
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package                      Arch   Version                        Repository
                                                                           Size
================================================================================
Installing:
 kernel-debuginfo             x86_64 2.6.32-358.2.1.el6.centos.plus debug 249 M
Installing for dependencies:
 kernel-debuginfo-common-x86_64
                              x86_64 2.6.32-358.2.1.el6.centos.plus debug  38 M

Transaction Summary
================================================================================
Install       2 Package(s)

Total download size: 287 M
Installed size: 1.6 G
Is this ok [y/N]: N

Another option is to download both the rpm packages (kernel-debuginfo and kernel-debuginfo-common) from this link. (look for the correct architecture as well as kernel version)