Tom H wrote:
On Fri, Jul 11, 2014 at 1:21 PM, Brian <ad44@cityscape.co.uk> wrote:On Fri 11 Jul 2014 at 12:21:57 -0400, Steve Litt wrote:A bizarre thought just popped into my head, in the form of a little voice. The little voice told me that if they guys who controlled the decision to go to systemd had been the decision makers in 1990, Linux would have a microkernel today.This thread has been quite interesting. In it a number concerns about system have been comprehensively answered. * Double-forking is not a problem. * Logs are in text format. * libsystemd-daemon0 doesn't affect users of other init systems. All useful stuff and (given the lack of substantial counter-argument) cause for regarding these questions as settled.The s/n ratio would be higher in threads such as these if people read the documentation...
Now that is a rather gratuitous and disingenuous statement.If one is installing a new program, the first time, reading the documentation is highly recommended. But this is a different situation entirely: Systemd is part of the o/s, and one that has a number of potential impacts - both intended and unintended - on all kinds of things, in non-obvious ways.
First off, one doesn't expect to have to pour through documentation every time one does an o/s upgrade. Just the release notes and the "before you upgrade" part of the installation instructions. Right now, the release notes for Wheezy simply say:
-------Debian 7.0 introduces preliminary support for systemd, an init system with advanced monitoring, logging and service management capabilities.
While it is designed as a drop-in |sysvinit| replacement and as such makes use of existing SysV init scripts, the |systemd| package can be installed safely alongside |sysvinit| and started via the |init=/bin/systemd| kernel option. To utilize the features provided by systemd, about 50 packages already provide native support, among them core packages like udev, dbus and rsyslog.
systemd is shipped as a technology preview in Debian 7.0. For more information on this topic, see the Debian wiki <http://wiki.debian.org/systemd>.
-------and the "preparing for update" section says nothing about systemd impacts to watch out for.
Of course the release notes and installation instructions for Jessie have yet to be written - it is, after all, "testing."
The documentation on the Debian wiki is likewise kind of sparse when it comes to "known issues and workarounds."
Documentation at the upstream site is a bit more comprehensive, if not well organized. You have to dig a bit to find things like: --- "If your distribution removes SysV init scripts in favor of systemd unit files typing "/etc/init.d/foobar start"
--- as a server admin, that's going to impact me, but--- but.. there's nothing in the Debian documentation that tells me if my "distribution removes SysV init files" (Wheezy, obviously not; but what about Jessie?)
- and then there's this page http://freedesktop.org/wiki/Software/systemd/Debugging/ -- which, upon reading, leads me to anticipate a lot of debugging -- and there are quite a few bugs listed in both the Debian and upstream bug trackers -- which is not counting bugs/impacts on packages, configurations, software that might be installed from source, administrative practices, and so forth
Now, I would hope that by the time Jessie gets released as stable, bugs and impacts have been minimized, and that the release notes and installation instructions are comprehensive when it comes to systemd impacts - but we're from there.
The discussions on this list are precisely what will lead to such documentation by: a. alert many of us to issues and impacts before we migrate (particularly impacts on things that won't be caught by package maintainers) b. provide input to package maintainers, and maybe upstream developers, on things that might need some work as a result of systemd c. provide raw material for the release notes and installation instructions for Jessie
In other words, a pox on your "read the documentation" snipe. Miles Fidelman -- In theory, there is no difference between theory and practice. In practice, there is. .... Yogi Berra