Unused services may seem like a non-issue, but they cause your server to take longer at boot, and they eat up RAM that could be used for critical services. This is a cross-platform issue, so Linux, Windows, BSD, and Solaris servers could all potentially have unused services running in the memory.
For example, Linux distributions and Mac OS X often come with CUPS enabled, but if you are using your box as a web server, CUPS, a printing server, is not something you need. Other unused services might include X.org (a graphical window server), bluetooth, hplip (another printing server), nfs (network file system), and many others. Find out what services you are not using and will not need and disable them.
To disable services from starting at boot in Redhat Enterprise Linux, CentOS, and Fedora, become root:
and type from the command line:
Scroll down to “System Services” and then remove the star from any of the services you do not need. Tab to “OK”, press Enter, and then tab to Quit and press Enter.