[CentOS] What are the differences between systemd and non-systemd Linux distros?

Wed Oct 17 19:03:41 UTC 2018
Warren Young <warren at etr-usa.com>

On Oct 17, 2018, at 10:03 AM, Mark Rousell <mark.rousell at signal100.com> wrote:
> launchd is not being forced on them as systemd is in practice

Try doing without launchd on macOS.

If you think that’s irrelevant, count the number of MacBooks at the next FreeBSD conference you attend.

For an init system to gain sufficient momentum, it must be the default, with no easy way to avoid it.  Without that, you get things like:

1. TrueOS, where major non-core services still have no OpenRC script despite OpenRC being the default for about a year.  There were no Samba or NUT OpenRC scripts the last time I tried TrueOS, for example.  Even if that’s changed, it’s still a reflection of the fundamental barrier to adoption that I’m talking about here.

2. Lazy third-party Linux packages that still use SysVInit scripts, because they’re just forward-porting old packages with minimal effort.

> I should add that the speaker also massively over-simplifies opposition
> to systemd on the basis that he incorrectly perceives it to be
> opposition to change. He seems to ignore the fact that, as above, there
> are substantive objections to the specific architecture and quality of
> systemd, not merely objections to change with no deeper reason.

While there certainly are objective problems with systemd’s design and implementation, it is basic human psychology that many people will not move to a newer system despite piles of advantages.  

The major BSDs are fundamentally conservative at the project management level, so I believe this tendency is stronger in the BSD user population than elsewhere in the IT world.  It’s a form of self-selection bias: the BSDs are run conservatively, so they attract a user base that is also technologically conservative, from which come the next generation of core developers, who therefore continue to run the project conservatively.  Consequently, the major BSDs are even more conservative than the Enterprise Linuxes.

If it were otherwise, TrueOS would have long since taken over the FreeBSD world, and nvi wouldn’t still be missing proper UTF-8 support.

> many people objecting to systemd
> would nevertheless favour more modern system/service management.

I’d love to see that quantified.

Alternatives to the BSD rc init system are readily available, yet I think if you were to survey actual use, you’d find that over 99% of BSD boxes use the stock init system.

Change has to be forced from the center out on this kind of thing.  Diffusion from the outside in takes too long.

The question in my mind is how long it’s going to take for the major BSDs to make such a change at the center, so that the majority of new installs will use a modern init system.  The systemd project started in 2005, and wasn’t widely deployed as the default until about 4 years ago.  If past is prologue, I think this won’t happen on the BSDs for another decade or so, if ever.

Example: FreeBSD is just now moving to pkg-in-base in earnest, giving it features I first saw in the default install of Debian in about 1995.