Upgrade CentOS 7.x to latest version
Usually, you want to use the last version of the operating system and if it is true you will update your OS early or later. In this article, you can found a simple and small instruction to update Centos 7 from 7.x to the latest version (now it is 7.4) See CentOS 7.4 release note for more information about changes.
Instructions
Check the current version
# cat /etc/redhat-release
CentOS Linux release 7.3.1611 (Core)
Upgrading is the same as the update option with -obsoletes flag.
Before upgrading purge all old cache and download a new one.
And next, you can upgrade OS.
yum clean all
yum makecache
yum -y upgrade
Below is described info that I got (I left only main info)
# yum clean all
...
Cleaning up everything
Cleaning up list of fastest mirrors
# yum makecache
...
Metadata Cache Created
# yum -y upgrade
...
Complete!
After the upgrade process has completed seeing changes reboot a system
systemctl reboot
And repeat to check the current version of the system
# cat /etc/redhat-release
CentOS Linux release 7.4.1708 (Core)
Of course, don’t do this procedure on a system with users.