Proper way to start xvfb on startup on centos?

I use the following init script to add and start xvfb on boot just blat that in /etc/init.d/ and run chkconfig xvfb on

   #!/bin/bash
   #chkconfig: 345 95 50
   #description: Starts xvfb on display 99
   if [ -z "$1" ]; then
   echo "`basename $0` {start|stop}"
       exit
   fi

   case "$1" in
   start)
       /usr/bin/Xvfb :99 -screen 0 1280x1024x24 &
   ;;

   stop)
       killall Xvfb
   ;;
   esac

And now, the systemd answer.

It has been almost four years since these questions and answers, and the world has changed whilst they have not. Since version 7, CentOS has used systemd. Ubuntu is mentioned in the question and in comments. Since version 15, Ubuntu has used systemd too.

Although one can use System 5 rc scripts under systemd, the scripts in answers here are highly suboptimal, to say the least. One blithely uses killall, whose problems for dæmon management are well known; and the other is a mess of rickety lock file and PID file logic none of which is actually necessary under a service manager, since service managers themselves keep track of dæmon processes.

As I have said elsewhere, if you're starting to learn this stuff and are on CentOS Linux version 7 or later or Ubuntu Linux version 15 or later, don't begin with System 5 rc scripts in the first place. Begin with systemd unit files.

a template for multiple Xvfb services

Simple xvfb.service systemd unit files for xvfb can be found at https://www.centos.org/forums/viewtopic.php?f=48&t=49080#p208363 and at https://askubuntu.com/a/621256/43344 . However, as I mentioned at the latter one can also take a templatized approach:

[Unit]
Description=virtual frame buffer X server for display %I
After=network.target

[Service]
ExecStart=/usr/bin/Xvfb %I -screen 0 1280x1024x24

[Install]
WantedBy=multi-user.target

As a locally-written, non-system non-packaged, unit file for system-wide (as opposed to per-user) services this goes into /etc/systemd/system/[email protected] of course.

controlling the services

One instantiates the template, into an actual named service, with the display number that is desired. For display :99, therefore, there is an actual service instance named xvfb@:99.service.

• Set the service to auto-start on bootstrap with systemctl enable xvfb@:99.service .
• Unset auto-starting the service with systemctl disable xvfb@:99.service .
• Start the service manually with systemctl start xvfb@:99.service .
• Stop the service manually with systemctl stop xvfb@:99.service .
• Inspect the current service status in detail with systemctl status xvfb@:99.service .

Further reading

• Stephen Wadeley (2014). "8. Managing Services with systemd" Red Hat Enterprise Linux 7 System Administrators' Guide. Red Hat.
• Lennart Poettering (2013-10-07). systemctl. systemd manual pages. freedesktop.org.
• https://unix.stackexchange.com/a/200281/5132

Here's a nice init script to accomplish this:

http://onemoretech.wordpress.com/2009/05/27/an-xvfb-init-script/

The script is:

#!/bin/bash
#
# /etc/rc.d/init.d/xvfbd
#
# chkconfig: 345 95 28
# description: Starts/Stops X Virtual Framebuffer server
# processname: Xvfb
#

. /etc/init.d/functions

[ "${NETWORKING}" = "no" ] && exit 0

PROG="/usr/X11R6/bin/Xvfb"
PROG_OPTIONS=":5 -screen 0 640x480x24"
PROG_OUTPUT="/tmp/Xvfb.out"

case "$1" in
    start)
        echo -n "Starting : X Virtual Frame Buffer "
        $PROG $PROG_OPTIONS>>$PROG_OUTPUT 2>&1 &
        disown -ar
        /bin/usleep 500000
        status Xvfb & >/dev/null && echo_success || echo_failure
        RETVAL=$?
        if [ $RETVAL -eq 0 ]; then
            /bin/touch /var/lock/subsys/Xvfb
            /sbin/pidof -o  %PPID -x Xvfb > /var/run/Xvfb.pid
        fi
        echo
        ;;
    stop)
        echo -n "Shutting down : X Virtual Frame Buffer"
        killproc $PROG
        RETVAL=$?
        [ $RETVAL -eq 0 ] && /bin/rm -f /var/lock/subsys/Xvfb
 /var/run/Xvfb.pid
        echo
        ;;
    restart|reload)
        $0 stop
        $0 start
        RETVAL=$?
        ;;
    status)
        status Xvfb
        RETVAL=$?
        ;;
    *)
     echo $"Usage: $0 (start|stop|restart|reload|status)"
     exit 1
esac

exit $RETVAL

Save the script as xvfbd and copy the script to /etc/init.d, then run the following command:

sudo chkconfig --add xvfbd

The simplest way is to add the following line into /etc/rc.local file (create one if it's not there):

Xvfb :0 -screen 0 1024x768x16 &

to start X virtual framebuffer on boot.