From RHEL-RT

Don't Run Extra Stuff - RHEL Tuning Tips

This is the oldest trick in the book, but sometimes overlooked. This info is generic RHEL applicable, not MRG Realtime specific.

• You'd be surprised at what we've found. Often there are services enabled which are completely unnecessary. For example:
  • Full GNOME desktop on servers for console over IP
  • Sendmail
  • Rpc stuff, nfs, etc
  • Console mouse (gpm)

• Also, your third party apps or other goodies added in by the hardware vendors
  • Ex: Hardware monitoring modules can be invasive