[ Thanks to LogError for this link.
]
“So here we go again. After you have exorcised all of the
daemons that were haunting your system, you might be interested in
all of the boring processes that occur when booting your linux. It
might seem a bit mystical right now, but it’s all quite
simple….“
“At the very beginning lets clear out that what we will discuss
here concernes only System V Init, so if you’re interested in
reading more about BSD Init you’ll have to do it quietly somewhere
else. As most of linux distributions use System V Init (ie, Red
Hat, SuSE and etc) I’ll make it not only the pin point of this
article but devote this entire article to it! Everything you can
read in this article has been written with SuSE linux in mind, so
please notice that some things may vary from distribution to
distribution.”
“System V Init uses run levels for determening modes of starting
the system and as usual, you’ll find that most linux distributions
use different systems of run level settings, so it may vary from
distribution to distribution. Basically, there are 7 run levels,
ranging from 0 to 6. In every distribution run level 0 stands for
halt, it stops the system, and run level 6 stands for reboot, and
of course it kicks you system with an old John Wayne boot.Other run
levels are 1, wich usually but not necessarily stands for single
user mode, usually used for administrating the system and other
admin related stuff. Other run levels, such as 2, 3, usually stand
for full multiuser mode, with or without graphical login. So, let’s
pretend you wish to switch login from ASCII one to a graphical, and
are running SuSE linux….”