Linux – How to determine the order of services that start from /etc/init.d

linuxsysvinit

ls -l /etc/init.d/ gives me a list of services are that are started on linux. How do I know the order in which the services are started?

Like if ls -l /etc/init.d/ lists out

serviceA
serviceB
serviceC

I want to know whether serviceB starts before serviceA and all. I want to know the oder of start

Best Answer

The /etc/init.d/ directory is not used. The actual directory used will be one of the /etc/rc*.d directories. Which one is dependent on which run-level your system enters. Typically you startup in runlevel 5 /etc/rc5.d/.

So if you want to find the order scripts will run in start there. The order these scripts are run depend on the name of symbolic link contained in the /etc/rc*.d directory. Scripts beginning with an S are executed when you enter the run level (at boot). Scripts beginning with a D are executed when it leaves this run level (eg: shuts down). Scripts are executed in file name order. That's why the symbolic links in these directories are named with numbers to put them in the "right" order.

So short answer... LC_COLLATE=C ls -l /etc/rc5.d whatever order that prints is the order they will run.

Related Solutions

Linux – Connection Between /etc/init.d and /etc/rcX.d Directories

Let's forget init.d or rcx.d and keep things very simple. Imagine you were programming a program whose sole responsibility is to run or kill other scripts one by one.

However your next problem is to make sure they run in order. How would you perform that?

And lets imagine this program looked inside a scripts folder for running the scripts. To order the priority of scripts you would name them in lets say numerical order. This order is what dictates the relation between init.d and rc

In other words init.d contains the scripts to run and the rcX.d contains their order to run.

The X value in rcX.d is the run level. This could be loosely translated to the OS current state.

If you dig inside the rcX.d scripts you will find this formatting:

Xxxabcd

X is replaced with K or S, which stands for whether the script should be killed or started in the current run level
xx is the order number
abcd is the script name (the name is irrelevant however where it points is the script this will run)

Debian – How to find out in which order /etc/init.d scripts are load on Debian

There's some files in /etc/init.d/ directory:

$ ls -al /etc/init.d/ | grep -i depend
-rw-r--r--   1 root root  2739 Feb 17 05:20 .depend.boot
-rw-r--r--   1 root root  2221 Feb 17 05:20 .depend.start
-rw-r--r--   1 root root  1855 Feb 17 05:20 .depend.stop

Whenever you run update-rc.d the files will change. .depend.boot file is for S level, .depend.start is for 2 3 4 5 levels and .depend.stop for 0 1 6.

In my case, I have the following order in .depend.start:

TARGETS = killprocs motd nvidia-kernel nfs-common rsyslog privoxy virtualbox
linuxlogo acpi-fakekey binfmt-support fancontrol openvpn hddtemp cgconfig 
dropbox-container dbus dnscrypt-proxy pulseaudio atd cryptmount exim4 
qbittorrent-nox ddclient acpi-support smartmontools ssh ntp loadcpufreq acpid 
cron rsync cgrulesengd cpufrequtils bootlogs bootchart-done single rmnologin 
rc.local stop-bootlogd

You can also see why the order presents in the way you see above. Each next line looks like this:

cgrulesengd: rsyslog cgconfig

which means that cgrulesengd needs rsyslog cgconfig to be started prior.

Best Answer

Related Solutions

Linux – Connection Between /etc/init.d and /etc/rcX.d Directories

Debian – How to find out in which order /etc/init.d scripts are load on Debian

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