Skip to main content

Migrate from RHEL7 to CentOS7


 

 

The following steps will convert a RHEL7 Linux server to CentOS7.

 

yum -y remove rhnlib redhat-support-tool redhat-support-lib-python
rpm -e --nodeps redhat-release-server
rpm -e --nodeps redhat-logos
rpm -e --nodeps yum
rpm -e redhat-indexhtml-7-13.el7.noarch
rpm -qa | egrep -i "rhn|redhat"
rm -rf /usr/share/doc/redhat-release/ /usr/share/redhat-release/
 
mkdir tmp && cd tmp
rpm --import RPM-GPG-KEY-CentOS-7
rpm -Uvh *.rpm

yum clean all
yum -y erase python-qpid-proton
yum -y upgrade
grub2-mkconfig -o /boot/grub2/grub.cfg
rm -rf /etc/yum.repos.d/redhat.repo
sync && init 6

 

That's it, after the restart your system is running CentOS7.

Comments

Popular posts from this blog

Manual Kubernetes TLS certificate renewal procedure

Intro Kubernetes utilizes TLS certificates to secure different levels of internal and external cluster communication.  This includes internal services like the apiserver, kubelet, scheduler and controller-manager etc. These TLS certificates are created during the initial cluster installation and are usually valid for 12 months. The cluster internal certificate authority (CA) certificate is valid for ten years. There are options available to automate certificate renewals, but they are not always utilised and these certs can become out of date. Updating certain certificates may require restarts of K8s components, which may not be fully automated either. If any of these certificates is outdated or expired, it will stop parts or all of your cluster from functioning correctly. Obviously this scenario should be avoided - especially in production environments. This blog entry focuses on manual renewals / re-creation of Kubernetes certificates. For example, the api-server certificate below...

Analysing and replaying MySQL database queries using tcpdump

Why There are situations where you want to quickly enable query logging on a MySQL Database or trouble shoot queries hitting the Database server in real-time. Yes, you can enable the DB query log and there are other options available, however the script below has helped me in many cases as it is non intrusive and does not require changing the DB server, state or configuration in any way. Limitations The following only works if the DB traffic is not encrypted (no SSL/TLS transport enabled). Also this needs to be run directly on the DB server host (as root / admin). Please also be aware that this should be done on servers and data you own only. Script This script has been amended to suit my individual requirements. #!/bin/sh tcpdump -i any -s 0 -l -w - dst port 3306 | strings | perl -e ' while(<>) { chomp; next if /^[^ ]+[ ]*$/;   if(/^(ALTER|COMMIT|CREATE|DELETE|DROP|INSERT|SELECT|SET|UPDATE|ROLLBACK)/i) {     if (defined $q) { print "$q\n"; }     $q=$_; ...

Enhancing Kubernetes Security: Enabling API Server Audit Logging

      In the ever-evolving landscape of container orchestration and management, Kubernetes remains at the forefront, empowering organizations to deploy, manage, and scale their containerized applications efficiently. However, as Kubernetes environments grow in complexity, ensuring robust security measures becomes paramount. One crucial aspect of Kubernetes security is audit logging, particularly concerning the Kubernetes API server, which serves as the primary point of interaction with the cluster. The Importance of Audit Logging Audit logging provides visibility into the activities and interactions within a Kubernetes cluster. By recording requests and responses made to the API server, audit logs offer valuable insights into user actions, system modifications, and potential security breaches. This transparency is essential for compliance with regulatory requirements such as HIPAA, GDPR, and PCI DSS, as well as for detecting and investigating security incidents. Understan...