Updating the kernel on Red Hat Linux or Cent OS Linux is a very simple process.
Check the kernel version of your Linux / Ubuntu / Cent OS server by following our tutorial.
NOTE: You can (and should) run Preupgrade Assistant multiple times to address anything that could cause problems before running the actual upgrade.
The Preupgrade Assistant will not harm your installed system.
Systems must be registered before updates from RHN can be applied. It can also be accessed via the command line by using the "rhn_register" command.
Registration requires local root access and a valid RHN login that has an unused Update or Management entitlement for the new system you want to register.