On Mon, Jul 18, 2011 at 01:22:37PM -0700, Steve Langasek wrote: > On Sun, Jul 17, 2011 at 06:51:17PM +0200, Lennart Poettering wrote: > > In fact, a minimal systemd system will win in almost very aspect against > > a remotely similarly powerful sysvinit system: you will need much fewer > > processes to boot. That means much shorter boot times. > > This is, as far as I'm aware, an unproven assertion. While it's true that > there is a cost to the additional processes used in init scripts, I have not > seen any serious attempt at measuring how big this impact actually is - > certainly not in terms that would be relevant to Debian, which uses dash as > its /bin/sh and insserv by default (in squeeze and above). > > I'm sure that systemd does much better than a traditional sysvinit boot with > /bin/bash and no dependency-based booting. But then, so does Debian's > current boot system, and so does upstart; and neither of the latter two > involve grandiose claims of a "shell-free boot". Trying to take the shell > completely out of the boot means a definite tradeoff here between boot speed > and configurability/maintainability, and in the absence of hard numbers, I > suspect this is a false optimization and not a trade-off that we actually > want to make in a general distribution. Which then calls into question the > use of such claims as a justification for a switch to systemd at all...
I'd expect some important differences between shell script based init and systemd-type init by the simple fact that there are (or at least should be, I don't know how systemd actually works) less files to read. Less files to read == less disk seeks. Disks seeks hurt startup performance. Mike -- To UNSUBSCRIBE, email to debian-devel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20110718211439.ga14...@glandium.org
