Re: [gentoo-user] Re: ntp-client slows down the boot process

[Aidan Harris]

On 27/07/2019 06:13, Ian Zimmerman wrote:

> Well, to play the anti-$DEITY advocate, you may also say that
> parallelizing helps you discover bugs in the dependencies that you
> otherwise never would.
>
> I have run fedora with systemd for a while, and I was able to make the
> boot wicked fast.  But it wasn't automatic, not due to systemd itself
> but due to packages like NetworkManager doing incredibly wasteful
> things by default.
>

Speaking parallel of bugs...

I run openrc with rc_parallel enabled and I end up booting so fast that 
by the time ntp-client starts DNS resolution is not properly available 
yet (I use a local DNS resolver so even though networking is up my local 
resolver takes a while - a small while, but enough of a while to be a 
problem - to be "ready") so the service fails to start. To work around 
this I added a few lines of shell to the start function:


# We boot so fast dns doesn't come up quickly enough
# By querying dns with nslookup we (hopefully) wait just long enough for 
it to come up properly
egrep '^server' /etc/ntp.conf | while read -r server
do
	set -- $server
	server="$2"
	nslookup "$server" > /dev/null 2>&1 && break
done

The second problem I had is even though I'm using rc_parallel ntp-client 
likes to block the rest of the boot (this is a laptop, I really don't 
need to block the whole boot just to make sure the time is set 
correctly). To work around that I used another hack by starting it from 
an @reboot cronjob.

I don't know what the proper idiomatic fix for these issues are, but 
booting too fast is a real problem (a problem that disappears if I 
disable rc_parallel but I want to boot fast!).

I've attached a bootchart showing ntp-client started from the default 
runlevel versus started via the @reboot cronjob (the difference is plain 
to see).