Replacing rc(8) (Was: FreeBSD Boot Times)

Doug Barton dougb at
Mon Jun 18 22:53:31 UTC 2012

It's unfortunate that this thread evolved into a discussion about
replacing rc.d, since that's almost certainly not relevant to the
original topic of improving the overall boot time.

If you analyze the boot process thoroughly you should see that out of
the total time taken to boot, nearly 0 is spent by rc.d actually doing
something. Almost all of the actual time is spent waiting for other
stuff, either the kernel (primarily) or the services that the system is
running actually starting up.

The latter item is the only place where making changes to rc.d is going
to help, and only then by parellelizing, and even then you are not
really going to gain much since most things at boot time are serial.

So while talk of how to get your favorite boot-time manager into FreeBSD
may be entertaining, it's not likely to be productive, and almost
certainly isn't going to help the goal of actually making the boot time

But, I'm willing to be proven wrong by someone who actually _implements_
one of these systems and can demonstrate, in a statistically rigorous
fashion, how much the boot time is improved.


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