Clean Core
| Version | Status | Date Updated | Updated By |
|---|---|---|---|
| 710 | Relevant to 0710 and older | 2nd June 2011 | purps |
| 810 | Not applicable | 2nd June 2011 | purps |
| 1004 | Not applicable | 3rd August 2011 | foxi352 |
| 1204 | Unknown | N/A | N/A |
| 1404 | Unknown | N/A | N/A |
| Usage Information | |||
Introduction
This page is meant to document the efforts to turn the LinuxMCE core into one or more Linux "services" that are automatically started at boot time. In other words, we would like to be able to boot a dedicated LinuxMCE Core server without using the Launch Manager application and without the dependency upon a graphic environment.
Please don't be shy to add any related knowledge you have.
Runlevels
Runlevels are an easy way to change how the system boots. LinuxMCE (as Kubuntu) uses runlevel 2 for normal operation (depending on the selections you made during installation) and runlevel 1 is used for rescue mode. The runlevels 0 and 6 are used for doing a shutdown or a reboot. Which leaves the runlevels 3, 4 and 5 free for us to experiment with.
As an example we will be setting up the following scheme in this document:
- rescue (as it is now)
- KDE (as installed by Kubuntu, like mainly-PC is now)
- Core (as in textmode, ideal for headless systems)
- Core + KDE (best of both worlds)
- LaunchManager (as the classic dedicated-MC setup is now)
Of course you can just adapt the example to your specific wishes or needs.
Starting another runlevel
If you just want to start a different runlevel once without modifying your startup scripts to much (as described below) You can simply boot into rescue mode by pressing [Esc] if grub tells you to and selecting it from the boot menu. That should boot up to a text console in single user mode, from there you can easily switch to another runlevel, for example runlevel 3:
telinit 3
The "runlevel" command will show you the previous and current runlevel.
Setting up the runlevels
Traditionally the runlevels are controlled by manipulating a set of "symbolic links" in the /etc/rcX.d/ directory, where X is the runlevel (0-6,S), however the Kubuntu system uses upstart, which has other ways as well.
When you are done with this you can switch to a different runlevel using one of the methods described elsewhere in this document, be sure to reboot in order to make a clean start.
Before starting it is always wise to make a backup of a few things, just in case:
tar cjvf ~/backup-`date '+%Y%m%d:%H%M'`.tar.bz2 /etc/init.d /etc/rc*.d
Preparation
Here are additional scripts needed to start the core devices, normally these task are performed by the launch-manager and it's startup script.
First a script for init (upstart):
cd /
cat >etc/init.d/core <<"EOF"
#!/bin/sh
case "$1" in
start)
/usr/pluto/bin/startCore.sh
;;
stop)
/usr/pluto/bin/StopCoreServices.sh
;;
*)
echo "Usage: /etc/init.d/core {start|stop}"
exit 1
;;
esac
exit 0
EOF
chmod +x etc/init.d/core
Which calls a script that determines the device number of the core device:
cd /
cat >usr/pluto/bin/startCore.sh <<"EOF"
#!/bin/sh
BASEDIR=/usr/pluto/bin
DeviceTemplate_Core=7
source $BASEDIR/SQL_Ops.sh
$BASEDIR/Config_Device_Changes.sh
$BASEDIR/Start_OrbiterGen.sh
$BASEDIR/UpdateMediaDaemonControl.sh -enable
$BASEDIR/Start_DCERouter.sh
$BASEDIR/checkforRaids.sh
$BASEDIR/UpdateAvailableSerialPorts.sh
QUERY="SELECT PK_Device FROM Device JOIN DeviceTemplate ON Device.FK_DeviceTemplate=DeviceTemplate.PK_DeviceTemplate WHERE PK_DeviceTemplate=${DeviceTemplate_Core}"
RESULT=$(RunSQL "$QUERY")
for ROW in $RESULT
do
CoreDev=$(Field 1 "$ROW")
$BASEDIR/startDevices.sh $CoreDev
done
EOF
chmod +x usr/pluto/bin/startCore.sh
And in turn calls this script to start the whole device family, excluding any media directors:
cd /
cat >usr/pluto/bin/startDevices.sh <<"EOF"
#!/bin/sh
BASEDIR=/usr/pluto/bin
DeviceTemplate_MeDi=28
source $BASEDIR/SQL_Ops.sh
DEVICES=$*
for DEVICE in $DEVICES
do
QUERY="SELECT ImplementsDCE, IsPlugin, Disabled, IF(PK_DeviceTemplate=${DeviceTemplate_MeDi},1,0) AS IsMeDi, REPLACE(DeviceTemplate.Description,' ','_') AS Description, CommandLine FROM Device JOIN DeviceTemplate ON Device.FK_DeviceTemplate=DeviceTemplate.PK_DeviceTemplate WHERE PK_Device=${DEVICE}"
RESULT=$(RunSQL "$QUERY")
for ROW in $RESULT
do
IMPLEMENTSDCE=$(Field 1 "$ROW")
ISPLUGIN=$(Field 2 "$ROW")
DISABLED=$(Field 3 "$ROW")
ISMEDI=$(Field 4 "$ROW")
DESCRIPTION=$(Field 5 "$ROW")
COMMANDLINE=$(Field 6 "$ROW")
# echo $RESULT, $IMPLEMENTSDCE $ISPLUGIN $DISABLED $ISMEDI $DESCRIPTION \"$COMMANDLINE\"
if [ "$ISMEDI" != "0" ]
then
echo "Device $DEVICE ($DESCRIPTION) is a Media Director"
continue
fi
if [ "$IMPLEMENTSDCE" = "0" ]
then
echo "Device $DEVICE ($DESCRIPTION) no DCE, going after the children"
CHILDREN=""
QUERY="SELECT PK_Device FROM Device WHERE FK_Device_ControlledVia=$DEVICE"
RESULT=$(RunSQL "$QUERY")
for ROW in $RESULT
do
CHILD=$(Field 1 "$ROW")
CHILDREN="$CHILDREN $CHILD"
done
if [ "$CHILDREN" ]
then
$0 $CHILDREN
else
echo "Device $DEVICE ($DESCRIPTION) has no children"
fi
else
if [ "$ISPLUGIN" = "0" ]
then
if [ "$DISABLED" = "0" ]
then
if [ -z "$COMMANDLINE" ]
then
COMMANDLINE=$DESCRIPTION
fi
if [ -x "$BASEDIR/${COMMANDLINE}" ]
then
# echo "/usr/bin/screen -d -m -S ${DESCRIPTION}-${DEVICE} $BASEDIR/Spawn_Device.sh ${DEVICE} ${DCERouter} ${COMMANDLINE}"
/usr/bin/screen -d -m -S ${DESCRIPTION}-${DEVICE} $BASEDIR/Spawn_Device.sh ${DEVICE} ${DCERouter} ${COMMANDLINE}
echo "Device $DEVICE ($DESCRIPTION) started ${COMMANDLINE}"
else
echo "Device $DEVICE ($DESCRIPTION) unable to start ${COMMANDLINE}"
fi
else
echo "Device $DEVICE ($DESCRIPTION) is disabled"
fi
else
echo "Device $DEVICE ($DESCRIPTION) is a plugin"
fi
fi
done
done
EOF
chmod +x usr/pluto/bin/startDevices.sh
On a Mainly Personal Computer installation
If you chose this install type you will need to create an extra startup script. In other words: when your core machine starts up with a KDE desktop. Here is a slightly simplified version of the one included in the "Dedicated Media Center" install type:
cd /
cat >etc/init.d/launch-manager <<"EOF"
#!/bin/sh
if [ "$1" == "start" ]
then
/usr/pluto/bin/Startup_Core-Hybrid.sh
fi
EOF
chmod +x etc/init.d/launch-manager
On a Dedicated Media Center installation
To make things a little bit easier for ourselves we're going to move a few things around a bit, this should give us about the same starting point as when using a "Mainly Personal Computer" setup. Do this if your core machine normally starts up with the launch manager:
cd / mv -iv etc/init.d/kdm etc/init.d/launch-manager cp -iv etc/init.d/kdm.saved etc/init.d/kdm
Changing the symlinks
In order to make the system boot only the core in runlevel 3, simply copy the symlinks of runlevel 2 and replace the ones that start KDE and the AVWizard with a symlink to the init script we created earlier during the preparations:
cd / rm -rfv etc/rc3.d/* cp -av etc/rc2.d/* etc/rc3.d/ ln -sfv ../init.d/core etc/rc3.d/S99core rm -fv etc/rc3.d/S99kdm etc/rc3.d/S990start_avwizard
Making the system boot the core + KDE in runlevel 4 is even simpeler as we don't even have to remove the symlinks:
cd / rm -rfv etc/rc4.d/* cp -av etc/rc2.d/* etc/rc4.d/ ln -sfv ../init.d/core etc/rc4.d/S99core
Starting the launchmanager in runlevel 5:
cd / rm -rfv etc/rc5.d/* cp -av etc/rc2.d/* etc/rc5.d/ ln -sfv ../init.d/launch-manager etc/rc5.d/S99launch-manager rm -fv etc/rc5.d/S99kdm
Additional upstart files to modify
You can edit these with your favorite text editor. In this example they are changed to start in runlevels 3-5 as well.
/etc/event.d/media-center-startup
start on runlevel 2 start on runlevel 3 start on runlevel 4 start on runlevel 5 stop on shutdown script /usr/pluto/bin/startup-script.sh end script
/etc/event.d/pluto-dhcpd-plugin
start on runlevel 2 start on runlevel 3 start on runlevel 4 start on runlevel 5 stop on shutdown script screen -d -m -S DhcpdPlugin /usr/pluto/bin/Dhcpd-Plugin.sh end script
On a sidenote: /etc/event.d/pluto-dhcpd-plugin seems redundant as it appears to be started from /usr/pluto/bin/startup-script.sh as well.
Changing the default runlevel
The default runlevel is 2, unless specified otherwise in the /etc/inittab file, here is an example on how to create such a file (it will override an existing one):
cd / cat >etc/inittab <<"EOF" # WARNING: Do NOT set the default runlevel to 0 (shutdown) or 6 (reboot). id:2:initdefault: # KDE #id:3:initdefault: # Core #id:4:initdefault: # Core + KDE #id:5:initdefault: # Launch Manager EOF
This specifies a default runlevel 2 (which it already was without this file anyway), you can use your favorite text editor to edit it to your desire when you permanently want to switch.
Note that the runlevel= options specified in the grub menu override this, at least if you have updated the /etc/event.d/rc-default file as described below.
Selecting a runlevel at boot time
This is a convenient way to experiment by simply selecting an alternative target from the boot-menu. If it doesn't work out you can always simply reboot to another runlevel.
First we need to replace one of upstart's files, /etc/event.d/rc-default. (It wasn't a big addition, but I didn't like the inconsistent way it was written originally, so I just cleaned it up a bit.)
cd /
cat >etc/event.d/rc-default <<"EOF"
# rc - runlevel compatibility
#
# This task guesses what the "default runlevel" should be and starts the
# appropriate script.
start on stopped rcS
script
runlevel --reboot || true
if grep -q -w -- "-s\|single\|S" /proc/cmdline
then
RL="S"
else
RL="$(sed -n -e 's/.*runlevel=\([1-5]\).*/\1/p' /proc/cmdline || true)"
fi
if [ -z "$RL" -a -r /etc/inittab ]
then
RL="$(sed -n -e 's/^id:\([1-5]\):initdefault:.*/\1/p' /etc/inittab || true)"
fi
if [ -z "$RL" ]
then
RL="2"
fi
telinit $RL
end script
EOF
Now edit /boot/grub/menu.lst with your favorite text editor as follows:
Comment out the "hiddenmenu" option as follows (this will show you the boot menu without having to press [Esc]):
## hiddenmenu # Hides the menu by default (press ESC to see the menu) #hiddenmenu
Copy the first boot target once for every runlevel you want to be able to start, and modify it to look something like this:
title LMCE 1.1 (0704) KDE root (hd#,#) kernel /boot/vmlinuz-2.6.20-15-generic root=UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx ro quiet splash runlevel=2 initrd /boot/initrd.img-2.6.20-15-generic quiet savedefault title LMCE 1.1 (0704) Core root (hd#,#) kernel /boot/vmlinuz-2.6.20-15-generic root=UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx ro quiet splash runlevel=3 initrd /boot/initrd.img-2.6.20-15-generic quiet savedefault title Ubuntu, kernel 2.6.20-15-generic root (hd#,#) kernel /boot/vmlinuz-2.6.20-15-generic root=UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx ro quiet splash initrd /boot/initrd.img-2.6.20-15-generic quiet savedefault
The last one is the original boot target, this will start whatever runlevel is set as the default (or runlevel 2 if none specified in /etc/inittab). It shouldn't take to much imagination to add targets for runlevels 4 and 5 as well.
You can also remove the quiet splash part if you want to see what is going on during boot.
Another section of interest could be:
## default num # Set the default entry to the entry number NUM. Numbering starts from 0, and # the entry number 0 is the default if the command is not used. # # You can specify 'saved' instead of a number. In this case, the default entry # is the entry saved with the command 'savedefault'. # WARNING: If you are using dmraid do not change this entry to 'saved' or your # array will desync and will not let you boot your system. default 0
Personal experience
Moved to the discussion/talk page.
