Before Starting(login to spacwalk server)
1.Create a base channel within Spacewalk (Channels > Manage Software Channels > Create New Channel)
2.systems->Activations Keys->Create Activation Key->RHEL65-key
[root@redhat01 ~]# rpm -Uvh http://yum.spacewalkproject.org/2.1-client/RHEL/6/x86_64/spacewalk-client-repo-2.1-2.el6.noarch.rpm
Retrieving http://yum.spacewalkproject.org/2.1-client/RHEL/6/x86_64/spacewalk-client-repo-2.1-2.el6.noarch.rpm
warning: /var/tmp/rpm-tmp.5zFl6X: Header V3 DSA/SHA1 Signature, key ID 863a853d: NOKEY
Preparing... ########################################### [100%]
1:spacewalk-client-repo ########################################### [100%]
[root@redhat01 ~]# BASEARCH=$(uname -i)
[root@redhat01 ~]# rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/$BASEARCH/epel-release-6-8.noarch.rpm
Retrieving http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
warning: /var/tmp/rpm-tmp.724ANT: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Preparing... ########################################### [100%]
1:epel-release ########################################### [100%]
[root@redhat01 ~]# yum install rhn-client-tools rhn-check rhn-setup rhnsd m2crypto yum-rhn-plugin
Loaded plugins: rhnplugin, security
This system is not registered with RHN.
RHN Satellite or RHN Classic support will be disabled.
epel/metalink | 10 kB 00:00
epel | 4.4 kB 00:00
epel/primary_db | 6.2 MB 00:01
spacewalk-client
[root@redhat01 ~]# rhnreg_ks --serverUrl=http://yum01.thsglobal.local/XMLRPC --activationkey=1-0d2570e6279642f2d1ee939aa7e156f3
refer link https://fedorahosted.org/spacewalk/wiki/RegisteringClients