On Fri, 10 Apr 2015 17:54:13 +0000
Isaac Dunham <ibid.ag@???> wrote:

> On Thu, Apr 09, 2015 at 08:30:25PM -0400, JeremyBekka C wrote:
> > I would like to say thanks to:
> > Robert Story, Shraptor, Nate Bargmann, KatolaZ, and Jude for your
> > very helpful advice. You gave me a lot to do and I look forward to
> > start digging in to the inner workings of the Linux OS.
[clip]

> Some other things that you may find helpful:
> -To get a better understanding of the init system, read some of the
> scripts in /etc/init.d/*; /etc/inittab; the manpages init(8), rcS(5)
> inittab(5), init-d-script(5), update-rc.d(8), insserv(8), and
> service(8); and /etc/init.d/rcS if you're really curious.
>
> -Try writing an init script or two, preferably for something that
> doesn't have one. Examples would include these busybox applets:
> acpid crond httpd rdate
> (Note-I wouldn't recommend keeping busybox httpd enabled.)
> Make sure to figure out the proper dependencies.

For extra credit, on a VM guest or experimental computer, install the
Epoch init system in parallel with whatever it came with. Experiment
with getting that running. Note that it's fairly easy to boot up, but
shutting down in a way that doesn't require a journal review on the
next boot is much more challenging. Note that the way to shut down when
initting from Epoch is by using the proper syntax of the epoch command,
*not* by running halt, shutdown, reboot, or init 6.

>
> -Learn to use debootstrap/chroot for installing Devuan/Debian.
> If you do this, you may want to read up on bind mounts and fstab
> first, as well as being sure you know how to set up networking and so
> on. Do this into an EMPTY partition, unless you're fine with losing
> data.
>
> If I were to guess, reading up on init and related things might take
> anywhere from a couple hours to a couple days; writing an initscript
> for the first time might be a couple hours; and a debootstrap install
> will probably take you at least a day the first time through.
>
> I'm not sure where to point you if you want to learn about openrc.

I'd recommend a VM guest or experimental computer with Manjaro, OpenRC
edition. Going through the init scripts of that distro really tuned me
in to how initting works. Please note that OpenRC isn't a complete init
system: the computer must be pre-initted by sysvinit or some other init
system, which then does little else but run the Virtual Terminals and
execute OpenRC.

Note also that OpenRC cannot run respawnable processes,
so if you want respawnable processes you must run them in sysvinit by
declaring them respawn in /etc/inittab, or you must run daemontools or
daemontools-encore on top of OpenRC, called by OpenRC, and from
daemontools respawn things.

I can't begin to tell you how much of an understanding I acquired by
hacking the OpenRC edition of Manjaro.

HTH,

SteveT

Steve Litt
Twenty Eight Tales of Troubleshooting
http://www.troubleshooters.com/28