Q. How do I start or stop X.Org from a command prompt?
A. X.org is open-source implementation of the X11 system. It is an open source X11-based desktop infrastructure. Xorg provides an interface between your hardware and the graphical software you want to run. Besides that, Xorg is also fully network-aware, meaning you are able to run an application on one system while viewing it on a different one.
Start X.Org Server
There are two ways, just type startx:
Alternatively, run init script such as /etc/init.d/gdm
# /etc/init.d/gdm start
$ sudo /etc/init.d/gdm start
Ctrl+Alt+Backspace – to stop server
Press Ctrl+Alt+Backspace to immediately kill the server – no questions asked.
Agian, you can use init script to stop session:
# /etc/init.d/gdm stop
$ sudo /etc/init.d/gdm stop
I don’t want firewall because I only run one http (port 80) public service. How do I turn off or disable firewall permanently under RHEL / Fedora Linux / Red Hat Enterprise Linux and CentOS Linux?
Iâ€™m using Debian Linux for last 4 years. Iâ€™m not able to find out update-rc.d like command ( install and remove System-V style init script links) on Redhat enterprise Linux (RHEL 5). Can you specify equivalent command for the same task?
Q. Under Red Hat or Cent OS chkconfig command provides a simple command-line tool for maintaining the /etc/rc[0-6].d directory hierarchy by relieving system administrators of the task of directly manipulating the numerous symbolic links in those directories. How do I control (or maintain Ubuntu runlevel) startup service under Debian or Ubuntu Linux with command line tool?
A. chkconfig is Redhat and friends only command. Debian or Ubuntu Linux offers different tools or command for same task.
Task: Command line tool to manage services / Ubuntu runlevel
update-rc.d automatically updates the System V style init script links /etc/rcrunlevel.d/NNname to scripts /etc/init.d/name. These are run by init when changing runlevels and are generally used to start and stop. For example turn on ssh service type the command:
# update-rc.d ssh defaultsOR
$ sudo update-rc.d ssh defaults
Task: Remove service
Again use update-rc.d command:
# update-rc.d SERVICE-NAME removeOR
$ sudo update-rc.d SERVICE-NAME remove
Task: Use Text based GUI Runlevel configuration tool to add or remove services
rcconf is Debian runlevel configuration tool. Rcconf allows you to control which services are started when the system boots up or reboots. It displays a menu of all the services which could be started at boot. The ones that are configured to do so are marked and you can toggle individual services on and off. If rcconf is not installed use apt-get command:
# apt-get install rcconfOR
$ sudo apt-get install rcconf Now run rcconf and just follow on screen instructions: