Redhat / Linux cheat sheet

Doing lots of fun stuff with red-hat enterprise server 4 at the moment.. And thought I'd write up some cheat-sheet style notes..

  • To check to see WHICH process is listening on which port, do: "lsof -i :".

    For instance, to see whats listening on this machine to port 25 - SMTP - do:

    # lsof -i :25

    smtp3738notes9uIPv49269TCP192.168.0.66 (LISTEN)

  • Red Hat Enterprise Linux version 4 intruduces the SElinux security subsystem - fantastic stuff. However, on most Domino Unix Startup Scripts, does cause issues. Daniel Nashed of NashCom has identified a fix to the file "/etc/pam.d/su" that prevents SElinux "promping" whilst performing the "su" command during the Domino Startup Script. In particular, this can prevent Domino starting up on an RHEL4 server.

    Download and use Daniels' Unix Startup Script (the best available), and specifically read the section at the bottom of the page regarding RHEL4 and the "su" command.