The most recent version of ClearOS 6.5 has been release a while ago but I still have ClearOS 6.4 on my server. I am planning to upgrade my ClearOS 6.4 installation to the new ClearOS 6.5 without having to re-install the whole thing. Fortunately, ClearOS 6.5 can be upgraded from previous ClearOS 6.4 or earlier. But, it does not support ClearOS 5.x version.
This tutorial is going to show you how to upgrade from ClearOS 6.4 to ClearOS 6.5. I attach the screenshots for each steps.
First, boot the server with the ClearOS 6.5 CD ROM. Download ISO if you don’t have it. Press Next on the first screen below.
Select the installation language
Select keyboard layout from the list. Leave the default value if you have no idea.
Select type of device. I use the first option “Basic Storage Devices”
Now we are on the most important step. Here, the installer auto detect the ClearOS 6.4 installed on the system. We must choose which scenario will be used. To create a fresh installation (destroy the previous installation) select the fist option. But if we want to upgrade the ClearOS 6.4 to ClearOS 6.5 we must select the second option.
We need to update the boot loader as well
Now the installation/upgrade process will start
When installation finished, reboot your server
Finally, ClearOS 6.5 is installed to replace ClearOS 6.4.