Difference between revisions of "Convert RH/OL To CentOS"

Latest revision as of 13:50, 14 June 2017

Note: 'cat /etc/redhat-release' shows RedHat or Oracle before these steps

1. browse to the centos repo to get the link for the latest centos-release package, right-click/copy link/url

http://mirror.centos.org/centos/5/os/x86_64/CentOS
http://mirror.centos.org/centos/6/os/x86_64/Packages
http://mirror.centos.org/centos/7/os/x86_64/Packages

2. wget the package/url (may need to specify a proxy, or use 'curl --proxy sc9-proxy.example.net:3128 -O http://mirror.centos.org/centos/6/os/x86_64/Packages/centos-release-6-8.el6.centos.12.3.x86_64.rpm')

ENT 5
# wget http://mirror.centos.org/centos/5/os/x86_64/CentOS/centos-release-5-11.el5.centos.x86_64.rpm 
[http://mirror.centos.org/centos/5/os/x86_64/CentOS/centos-release-notes-5.11-0.x86_64.rpm
ENT 6
# wget http://mirror.centos.org/centos/6/os/x86_64/Packages/centos-release-6-9.el6.centos.12.3.x86_64.rpm
ENT 7
# wget http://mirror.centos.org/centos/7/os/x86_64/Packages/centos-release-7-3.1611.el7.centos.x86_64.rpm

3. install centos-release (plus release notes dependency for RedHat 5) and remove redhat-release
Note: 'cat /etc/redhat-release' shows CentOS after this step

RedHat 5
# rpm -i --force centos-release-5-11.el5.centos.x86_64.rpm centos-release-notes-5.11-0.x86_64.rpm
# rpm -e redhat-release-5Server redhat-release-notes-5Server
RedHat 6
# rpm -i --force centos-release-6-9.el6.centos.12.3.x86_64.rpm
# rpm -e redhat-release-server
RedHat 7
# rpm -e --nodeps redhat-release-server
# rm -rf /usr/share/redhat-release /usr/share/doc/redhat-release /etc/system-release-cpe.rpmsave /etc/os-release.rpmsave
# rpm -i --force centos-release-7-3.1611.el7.centos.2.10.x86_64.rpm

4. system can now be subscribed to CentOS spacewalk channel with --force option, or add CentOS-Base.repo to /etc/yum.repos.d/CentOS-Base.repo

5. remove additional RedHat packages and replace with corresponding CentOS packages

RedHat 5
# yum update redhat-logos
# rpm -e redhat-support-tool redhat-support-lib-python redhat-menus htmlview Deployment_Guide-en-US 
NOTE : order is important for RPM dependencies
RedHat 6
# rpm -e --nodeps redhat-indexhtml
# yum install centos-indexhtml
# yum update redhat-logos
# rpm -e redhat-support-tool redhat-support-lib-python redhat-access-insights subscription-manager
IF you see a yum message about lynx-2.x.x-xx.el6.x86_64 has missing requires of redhat-indexhtml
# yum reinstall lynx
RedHat 7
# rpm -e --nodeps redhat-indexhtml redhat-logos
# yum install centos-indexhtml centos-logos
# yum update abrt redhat-menus
# rpm -e redhat-support-tool redhat-support-lib-python redhat-access-insights subscription-manager Red_Hat_Enterprise_Linux-Release_Notes-7-en-US