How do I make CPanel/CentOS recognize the new disk space
I received a free upgrade of my Linode plan, however when I run the
"df -h" command I still see the same free space available before the upgrade
Did you make sure to also resize your Linode's disk? The disk resize is not automatic, so even after a free plan upgrade you still need to issue a disk resize from the Manager.
This guide will walk you through that process:
The process is totally safe, though it does require that you power off and restart your Linode. Make sure that you've configured your Linode to handle reboots properly, especially when it comes to firewall settings and configuring vital services to resume on startup. You can find specific instructions in Linode's Reboot Survival Guide here: