[lug] Thoughts on upgrading to CentOS 7

[Steve Litt]

On Wed, 28 Mar 2018 10:13:14 -0600
Zan Lynx <zlynx at acm.org> wrote:

> On 03/28/2018 06:43 AM, Alan Robertson wrote:
> > People like to say that technology wins in open source. This
> > appears to be a counterexample.  
> 
> Well, I'm not going to be quiet and let others think there's some kind
> of consensus against systemd.
> 
> Here's my opinion. Systemd is better in every single way than the
> ridiculous pile of hacked together "SysV" init scripts.

Let's say you're right about systemd being better than sysvinit. So
what? There are several alternatives far superior to either.

[snip]

> The "solutions" to the SysV problems, like runit just pile on more
> complexity to a broken system. Systemd just fixes it.

Have you used runit? It's the simplest system on the planet, in terms
of conceptualization, in terms of installation, in terms of building
from scratch.


> And daemons that do stupid things, worked around with shell script
> hacks like tail grepping the log file? 

That all goes away with either runit or s6.

> They got fixed with real
> startup notification.

And that's a good thing. Please keep in mind though, what happened is
the daemon authors finally decided to notify. S6 has a notification
system requiring only the writing of a newline to (IIRC) a fifo.
Startup notification doesn't require the massive monolithic
entanglement of systemd.

Also, it's very easy with runit and s6 for the process supervisor to
test for the readiness of a daemon on which it depends, and test with a
lot more accuracy than most authors' notifications.

> 
> Instead of applying another coat of paint to the rotten wood it's been
> ripped out and replaced correctly.

My point exactly. Rip out the monolithically entangled, complex,
constant attention requiring systemd and replace with
easy-works-every-time runit or s6.

> 
> So technology finally did win out.

:-)


SteveT

Steve Litt 
April 2018 featured book: Troubleshooting Techniques
     of the Successful Technologist
http://www.troubleshooters.com/techniques