Fix “Error: rpmdb open failed” on CentOS or Amazon Linux 2

Yesterday, I have started to test some services on running Amazon Linux 2 powered by Amazon Web Services cloud. For some reason, my package manager yum is broken and when I started to update my yum database, I’ve got an error about rpmdb open failed. You can see my error below. If you are running on Centos7 or another Linux […]

Find the exact size of certain files in Linux

One day, there may be a lot of files in more than one extension in the macOS, Linux or server you use, and you may be wondering about the size of these files or just want to see the size of the files with the corresponding extension for a specific study. The other day, the server I was working on […]

Disable SELinux on CentOS 7 or CentOS 8

This tutorial shows you how you can disable SELinux (Security-Enhanced Linux) on your CentOS server. The CentOS version should be 7 or 8. The version does not matter. What is SELinux? SELinux is a security mechanism directly controlling by the kernel. It allows administrators and users more control over access controls on access based SELinux policies. SELinux has three different […]