[TriLUG] rc.X -- how do the real sysadmins do it?

[Ben Pitzer]

The *nix SysV standard, to which most Linux distros adhere, is to place the
actual init script in the /etc/init.d directory, then symlink in the
appropriate rc?.d directory to the file in /etc/init.d.  BSD, on the other
hand, uses the original Unix style, now commonly referred to as BSD init
scripting, which is to place all of the startup information in a single
file, called rc?.d.  My personal preference is the SysV style, as it does
allow for better process management on an individual service-to-service
level.  I'd rather run '/etc/init.d/servicename stop' than 'kill <pid>' to
stop a process.  Now, many of you out there are fans of the 'service'
command.  I have nothing against it, I suppose, but I learned many moons ago
where the init scripts live, and how to use them, and I'm more of a fan of
doing that.

Now, insofar as actually deleting the files in the /etc/rc?.d directories
goes, I'm against it on the simple basis that sometimes different software
manufacturers and package maintainers will place actual scripts in the rc?.d
directories, rather than symlinks.  Deleting these would be quite bad, as it
means that they wouldn't be there later in case you want to re-enable the
service.  Additionally, someone suggested using a lower case 's' instead of
the standard uppercase 'S' in the script/symlink name.  This doesn't work on
some distros, as any 's', upper or lowercase, is recognized.  Finally, by
adding norun. onto the beginning of the script/symlink name in the rc?.d
directory, you preserve everything about the file, without changing either
it's original form, or creating any confusion about that service's initial
configuration.  norun.S99svcname is quite obviously a service that was
scheduled to start after all other services, but has been disabled.
K99svcname might confuse future admins into thinking that the service was
never supposed to run, which is another reason why I'm somewhat (yes, I can
think of both arguments, and I'm still somewhat...) opposed to using
'service' to turn init scripts on or off.

My methodology, which I learned from some highly experienced sysadmins over
the years, has advantages in that it leaves no confusion as to the original
intention of the script, and leaves the script available to be re-enabled at
any time the admin chooses using a simple 'mv' command.  Sometimes it's not
just about making it easy, but also making it clearly recognizable.

Again, my $0.02, but my advice, Ryan, is to choose whichever setup works
best for your situation, as always.

Regards,
Ben Pitzer

---------------------------------------------

"Those that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
 --Ben Franklin--





> -----Original Message-----
> From: trilug-bounces at trilug.org [mailto:trilug-bounces at trilug.org]On
> Behalf Of James Manning
> Sent: Wednesday, December 03, 2003 10:28 AM
> To: Triangle Linux Users Group discussion list
> Subject: Re: [TriLUG] rc.X -- how do the real sysadmins do it?
>
>
> > On some systems  it is common to have all the scripts in /etc/init.d
> > and just have links in /etc/rc?.d. So to remove something just remove
> > the link in /etc/rc?.d, but not the original in /etc/init.d. This give
> > you the ability to start/stop manually but not when changing run
> > levels.
>
> I'm kinda curious - on which Linux-based systems is this not the case?
> I ask only because my experience is limited to Debian and RHL kinds of
> distros (well, outside of SLS and Slackware way back in the day, but
> I've forgotten all that now) which do the symlink thing so I'm curious
> :)
>
> The symlinks are important since the name of the symlink determines
> the start-up order (that parallel-start init would be nice with its
> "better" dependencies).  I miss RHL's chkconfig on my Debian systems
> for that reason - nothing about the service "knows" which number it
> should start/stop at, so while update-rc.d with "defaults" as the
> param is usually ok, it's not an always-works kind of thing like
> "chkconfig foo on" would be.
>
> --
> James Manning <http://www.sublogic.com/james/>
> GPG Key fingerprint = B913 2FBD 14A9 CE18 B2B7  9C8E A0BF B026 EEBB F6E4
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