NO TO SYSVINIT - or initscripts, rather!
NO TO SYSVINIT - or initscripts, rather!
Posted Nov 1, 2018 14:56 UTC (Thu) by rweikusat2 (subscriber, #117920)In reply to: NO TO SYSVINIT - or initscripts, rather! by rweikusat2
Parent article: Init system support in Debian
Posted Nov 2, 2018 18:56 UTC (Fri)
by jccleaver (guest, #127418)
[Link] (6 responses)
I'm not sure about the "certainly" there. Arguably? Yes. Certainly? No.
I can count the number of unexpected boot hangs traced back to a problem with the rc.sysinit or related bootup scripts in non-systemd systems going back to 2000 on maybe one hand, with the only regular issue being sendmail hanging the boot on a lack of DNS resolution of the local hostname. Virtually every other hang has been a result of hardware, or daemon bugs.
systemd is too clever for its own good in trying to parallellize boot, meaning the "init system" is much more likely to fail in unexpected and hard to trace ways. upstart, of course, is capable of "parallellizing" things too... but, crucially, in RHEL 6 this wasn't actually used. The vast majority of the boot logic was in /etc/rc.sysinit, not /etc/init/*. If systemd did the same a significant number of problems would be avoided. (Even if other philosophical problems remained.)
systemd proposes, and then implements, a paradigm shift among things that used to be discrete, including "the init system", as opposed to PID 1. I think there's room for reductionist debate at all levels.
Posted Nov 2, 2018 19:45 UTC (Fri)
by mpr22 (subscriber, #60784)
[Link] (5 responses)
AFAIK systemd doesn't do anything particularly "clever" when it comes to parallelizing system startup, but rather just says that by default, any pair of units which do not state themselves to require serialization with respect to each other shall be assumed parallelizable.
Posted Nov 2, 2018 20:28 UTC (Fri)
by xtifr (guest, #143)
[Link] (4 responses)
And yet, when Debian switched over to systemd as a default, it still reduced my boot time by an order of magnitude!
(Note that I do not really have any strong opinions about init systems one way or the other. But despite switching to systemd as part of Debian's automatic updates, and, more recently, because of a re-install of my system partitions from scratch, the only difference I've observed is a faster, cleaner boot. Heck, even my log files are still working the way I'm used to. Which rather surprised me, since "I hate binary log files" is one of the few complaints I've heard about systemd that actually had me at all worried.)
Posted Nov 2, 2018 20:56 UTC (Fri)
by lkundrak (subscriber, #43452)
[Link] (3 responses)
I have no idea how could I have lived without journalctl --since '5 minutes ago'.
Posted Nov 2, 2018 21:50 UTC (Fri)
by jccleaver (guest, #127418)
[Link] (2 responses)
tail -200 /var/log/messages ?
(and maybe adjust your number if you guessed your log velocity wrong)
Posted Nov 2, 2018 23:39 UTC (Fri)
by Cyberax (✭ supporter ✭, #52523)
[Link]
Posted Nov 5, 2018 11:57 UTC (Mon)
by jond (subscriber, #37669)
[Link]
NO TO SYSVINIT - or initscripts, rather!
NO TO SYSVINIT - or initscripts, rather!
NO TO SYSVINIT - or initscripts, rather!
> "I hate binary log files" is one of the few complaints I've heardNO TO SYSVINIT - or initscripts, rather!
NO TO SYSVINIT - or initscripts, rather!
NO TO SYSVINIT - or initscripts, rather!
NO TO SYSVINIT - or initscripts, rather!