[lug] Thoughts on upgrading to CentOS 7

[Steve Litt]

On Wed, 28 Mar 2018 17:53:46 -0600
Rob Nagler <nagler at bivio.biz> wrote:

> On Wed, Mar 28, 2018 at 10:56 AM, Steve Litt wrote:
> 
> > Yeah, that's what I was saying. Once a distro has systemd, swapping
> > in runit or s6 becomes extremely difficult. I'm not sure what other
> > context one could view it from.
> >  
> 
> Firstly, I have to say I appreciate people like you. We wouldn't have
> such stable distros without you! It's very important for people to
> dig into the distros to try to keep them honest and robust.
> 
> Secondly, my focus is different. My problems have nothing to do with
> the distro per se other than it is much harder to upgrade from CentOS
> 6 to 7 than I (naively) thought it should be. I don't think systemd
> made it that much harder other than it being buggier than I would
> have liked.
> 
> Back to your statement, which is sort of a question...
> 
> There are distro providers and distro users. I'm a distro user. 

Now I see what you mean.

Let me posit a question: Is being a distro user a switch, as in either
you are or you aren't, or is it a spectrum? Have you noticed that some
people are more likely to modify their distro than others?

Seems like almost a decade since Ubuntu switched from Gnome to Unity.
All of a sudden, there was a charge for the exits as people dumped
Ubuntu to avoid Unity. I used Ubuntu at the time, and my 20 minute
solution was apt-get install xfce. I chose to keep Ubuntu but tailored
it to my taste.

The people who left Ubuntu were farther on the Distro User spectrum
than I was. 

Few of us use Linux From Scratch. Most use distros with package
managers. And of those who do, there's a spectrum spreading between
those using Linux only as the distro intended, and those who pick a
good distro, consider that's close to what's needed, and then tailor
the rest to fit our exact needs. And of course there's everything
between those two extremes.


> A
> distro provider can change out packages more easily than distro
> users, because they are experts in their distro and the general
> concept of building distros. 

No doubt about that.

> As a distro user, I am buying into a lot
> of policy decisions such as "we like systemd and gnome." 

Yes and no. Systemd is a special case. If one doesn't like Gnome, it's
a 20 minute deal and maybe a few shellscripts to replace it. You can
have Emacs, Vim and Bluefish on the same computer. If your distro
doesn't provide you with the Sigil ePub authoring tool, with most
distros you can build it yourself (tough job, lots of dependencies).
Most non-Redhat distros give you packages for ten or so WM/DEs (Window
Managers or Desktop Environments). I'd say the only distro policy
you're absolutely stuck with is rolling release vs version release, and
often compile-to-install vs binary install. Given the knowledge,
desire and time, you could swap runit for systemd on most distros, but
as a practical matter few would.


> A distro
> user is going to find it hard to switch out many policy decisions. My
> job as a distro user is picking the right distro. You asked me that
> earlier in this thread, and you are correct that maybe I should have
> considered a different distro since the change from CentOS 6 to 7 has
> caused me much more work than I (naively and incorrectly)
> anticipated. My bad for not being a more discriminating distro
> user/chooser, 

:-)

Linux has been my exclusive OS (except brief bouts with BSD) since
March of 2001, and I've seen several cases of good distros gone bad.
You can't blame yourself for choosing the distro when it was still good.

> but I don't have the urge to pop and swap runit for
> systemd. 

Probably not. Systemd, along with version vs rolling and binary vs
compile install, are foundational policies of the distro you're better
off just accepting.

And it's not like systemd is a major fiasco now. I'm thinking a few
million dollars are spent each year employing people to grow systemd
while keeping it running to a reasonable degree, as long as people use
the distro the way the distro envisioned. Whether they'll be able to
keep this ever growing behemoth running in years to come requires a
crystal ball. If they can't, as long as there are sans-systemd distros
to switch to, all is well.

Want to have some fun? I assume you have qemu or Virtualbox. Make
yourself a Void Linux VM guest, which of course comes with runit.
Install a time server. Notice how you can turn the time server on and
off with the sv command, how you can prevent it from running at boot by
putting a file named "down" in the directory. Notice how simple the run
scripts are. Run scripts are the equivalent of Unit Files and Init
Scripts, but unlike sysvinit and OpenRC init scripts, they're very
simple, almost always less than 10 lines. Notice how a mere mortal can
understand the workings of runit. I'm not suggesting you dump systemd
when it's doing what you need, I'm just suggesting you get familiar
with runit, as a sort of Plan B or diversification of your knowledge
assets.

 
SteveT

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