CentOS 8/9 update installed packages for security

To update all installed packages for security on CentOS 8/9, you can use the dnf package manager.

1. First, update the package repository information by running the following command:

sudo dnf check-update

This will download the latest package repository information from the configured package sources.

2. To update all installed packages for security, you can use the dnf upgrade --security command. This will update all packages that have security updates available:

sudo dnf upgrade --security

3. If you want to update all installed packages, including those that do not have security updates available, you can use the dnf upgrade command without the --security flag:

sudo dnf upgrade

This will update all installed packages to the latest available version.

Note: Before running the update commands, you may want to review the list of packages that will be updated by using the dnf updateinfo list updates command. This will show you a list of all available updates, along with a description of each update.

After running the update commands, you may need to reboot your system in order for the updates to take effect. You can use the reboot command to reboot the system, or you can reboot manually by shutting down and restarting the system.

It's a good idea to regularly update your system to ensure that you have the latest security fixes and other updates installed. You can set up automatic updates using the dnf-automatic package, which will automatically download and install updates on a schedule that you specify.