To Upgrade/Migrate a Red Hat Linux 4 to cent OS(4.9) follow the stepby step Guide.
Firstly, do a cleanup:
yum clean all
Then, create a working space where RPMs can be downloaded:
mkdir ~/centos
cd ~/centos
Now download the relevant CentOS key and import it:
wget http://vault.centos.org/4.9/os/x86_64/RPM-GPG-KEY-centos4
rpm –import RPM-GPG-KEY-centos4
Then, get relevant packages from CentOS – note these instructions will pull i386 packages or x86_64 packages depending on your system:
wget http://vault.centos.org/4.9/os/x86_64/CentOS/RPMS/centos-release-4-8.x86_64.rpm
wget http://vault.centos.org/4.9/os/x86_64/CentOS/RPMS/yum-2.4.3-4.el4.centos.noarch.rpm
wget http://vault.centos.org/4.9/os/x86_64/CentOS/RPMS/yum-metadata-parser-1.0 8.el4.centos.x86_64.rpm
wget http://vault.centos.org/4.9/os/x86_64/CentOS/RPMS/python-elementtree-1.2.6-5.el4.centos.x86_64.rpm
wget http://vault.centos.org/4.9/os/x86_64/CentOS/RPMS/python-sqlite-1.1.7-1.2.1.x86_64.rpm
wget http://vault.centos.org/4.9/os/x86_64/CentOS/RPMS/python-urlgrabber-2.9.8-2.noarch.rpm
wget http://vault.centos.org/4.9/os/x86_64/CentOS/RPMS/python-sqlite-1.1.7-1.2.1.x86_64.rpm
wget http://vault.centos.org/4.9/os/x86_64/CentOS/RPMS/sqlite-3.3.6-2.x86_64.rpm
wget http://vault.centos.org/4.9/os/x86_64/CentOS/RPMS/sqlite-devel-3.3.6-2.x86_64.rpm
If you don’t want to use wget other option is to connect using elinks to connect to CentOS repository.
Using elinks allows you to get the most recent version without stumbling over the version number – if the package is updated, you don’t have to guess at the version numbers in the filename.
elinks http://vault.centos.org/4.9/os/x86_64/CentOS/RPMS/
Now update all of the packages that were downloaded:
rpm -Uvh –force *.rpm
warning: centos-release-4-8.x86_64.rpm: V3 DSA signature: NOKEY, key ID 443e1821
Preparing… ########################################### [100%]
Repackaging…
1:redhat-release ########################################### [100%]
Upgrading…
1:sqlite ########################################### [ 13%]
2:python-sqlite ########################################### [ 25%]
3:yum-metadata-parser ########################################### [ 38%]
4:python-elementtree ########################################### [ 50%]
5:python-urlgrabber ########################################### [ 63%]
6:centos-release ########################################### [ 75%]
7:sqlite-devel ########################################### [ 88%]
8:yum warning: /etc/yum.conf created as /etc/yum.conf.rpmnew
########################################### [100%]
Ensure that in your “/etc/yum.repos.d/” directory there are not “redhat” related files, If found remove them.
Copy over the yum.conf which was renamed during installation.
cp –p /etc/yum.conf.rpmnew /etc/yum.conf
Edit /etc/yum.repos.d/CentOS-Base.repo and replace base and update repos entries as below:
[base]
name=CentOS-$releasever – Base
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
#mirrorlist=http://vault.centos.org/?release=$releasever&arch=$basearch&repo=os
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
baseurl=http://vault.centos.org/4.9/os/$basearch
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
priority=1
protect=1
#released updates
[update]
name=CentOS-$releasever – Updates
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
#mirrorlist=http://vault.centos.org/?release=$releasever&arch=$basearch&repo=updates
#baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
baseurl=http://vault.centos.org/4.9/updates/$basearch
gpgcheck=1
#gpgkey=http://vault.centos.org/centos/RPM-GPG-KEY-centos4
gpgkey=http://vault.centos.org/4.0/os/x86_64/RPM-GPG-KEY-centos4
priority=1
protect=1
#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever – Addons
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=addons
#baseurl=http://mirror.centos.org/centos/$releasever/addons/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
priority=1
enabled=0
protect=1
#additional packages that may be useful
[extras]
name=CentOS-$releasever – Extras
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
#baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/
enabled=0
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
priority=1
protect=1
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever – Plus
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
#baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
priority=2
protect=1
#contrib – packages by Centos Users
[contrib]
name=CentOS-$releasever – Contrib
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
#baseurl=http://mirror.centos.org/centos/$releasever/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
priority=2
protect=1
Lastly, perform an upgrade to fully update the system from the new CentOS repositories:
yum upgrade
This will upgrade the server to cent OS 4.9.
For best practices, you probably should reboot here as well – thus loading new libraries, deleting old files, and activating right kernel.
Once server is rebooted ensure that we have restored back the perl softlink as it gets removed after conversion.
