I've been using Plex Media Server now for nearly a year and unfortunately if you run the system through Cent OS command line there is no automatic way of updating it. This little guide will go through the process of ssh'ing into your media server, downloading the latest version and then manually installing it.
To see which version of Plex you are running simply log into your web interface for your media server and go to Settings > Server > General you will see something similar to the screenshot below.
Now check the Plex website to see if there is a newer version available for Cent OS. If there is then it's time to ssh into your media server.
Where USER is the user of your media server and SERVERADDRESS is the IP or domain name of your media server. Now we need to navigate to a directory that the update can be downloaded into. I download mine into /home/install using this example the code would be.
Now we need to download the update, copy the url from the plex website, as of today that would be http://downloads.plexapp.com/plex-media-server/0.9.9.12.504-3e7f93c/plexmediaserver-0.9.9.12.504-3e7f93c.x86_64.rpm now in your ssh terminal type the following
Were the filename is the link you just copied from Plex. You should then see the download begin, if it doesn't work double check your link.
After is has completed you need to shutdown the Plex service running on the media server. This is done with the following:
service plexmediaserver stop
After a couple of seconds you should see something similar to the following
Now that Plex is stopped we can run the manual install, run the following command (where the filename is the same as the file you downloaded from plex).
yum localupdate plexmediaserver-0.9.9.12-504-3e7f93c.x86_64.rpm
After a minute the update should be installed and you are ready to restart your server. Use the following command:
service plexmediaserver start
Congratulations, Plex is updated to the latest version.