[arch-general] Optimizing boot

[Toyam Cox]

On Tue, Apr 29, 2014 at 8:09 PM, Daniel Micay <danielmicay at gmail.com> wrote:

> On 29/04/14 07:55 PM, Toyam Cox wrote:
> > On Tue, Apr 29, 2014 at 7:47 PM, Daniel Micay <danielmicay at gmail.com>
> wrote:
> >
> >> On 29/04/14 07:34 PM, Toyam Cox wrote:
> >>> On Tue, Apr 29, 2014 at 7:20 PM, Simon Brand
> >>> <simon.brand at postadigitale.de>wrote:
> >>>
> >>>>
> >>>>
> >>>> Am 30.04.2014 00:06, schrieb Toyam Cox:
> >>>>> NetworkManager.service is running for 12 seconds
> >>>>
> >>>> Can you use static ip address in your network?
> >>>> The dhcp client did eat a lot of time here, too.
> >>>> 9 sec boot here without cryptsetup and static ip.
> >>>> Server needs 20 sec without ssd, 15 sec for dhcpcd, mysql and php-fpm
> >>>>
> >>>>
> >>> I do not believe that would help, because often I start up in areas
> >> without
> >>> a network. Perhaps there is a way to get Network Manager to start after
> >> the
> >>> boot is completed, or at least not be a boot dependency?
> >>
> >> NetworkManager works fine with roaming and can be configured to use a
> >> static IP on some networks but not others. I don't see what you have to
> >> gain by removing it from the regular boot process... just make sure
> >> you're not letting stuff block on it.
> >>
> >> This is with NetworkManager enabled on a wireless network with a Samsung
> >> 840 EVO (it varies from ~2-3s for kernel + userspace):
> >>
> >> Startup finished in 3.070s (firmware) + 60ms (loader) + 1.655s (kernel)
> >> + 676ms (userspace)
> >>
> >> 160ms NetworkManager.service
> >>
> >> AFAIK it doesn't count the time needed to connect over DHCP... it's
> >> often not connected by the time I have a browser and a few terminals
> >> open in i3 since it takes 10 seconds.
> >>
> >> Not that boot time should matter to anyone, since kernel upgrades aren't
> >> every day and there's not much reason to reboot otherwise :P.
> >>
> >>
> >
> > So something seems to be wrong here.
> > Startup finished in 4.637s (firmware) + 131ms (loader) + 2.790s (kernel)
> +
> > 20.066s (userspace) = 27.626s
> >
> >> 12s NetworkManager.service
> >
> > What sort of things should I check for? Is there an /etc config file I
> can
> > play with?
>
> Use an efistub loader like gummiboot if you're not already, use lz4
> compression for the kernel, disable staggered spin-up, use a single
> unsplit root partition and avoid remounting it, etc. I'm sure these
> things are all on the wiki somewhere, because I remember writing some of
> it.
>
> There's not really any magic to speed up starting a large number of
> services, if that's what you're doing. All I have enabled is
> chrony/pdnsd/NetworkManager and they don't block the boot process. I
> just use agetty to start up i3.
>
> I assume you've got something on the critical path depending on
> NetworkManager like a Type=idle service.
>
>
I read the wiki page today, actually. I have 1 root partition, and another
for /usr and another for /var. / is /sda2, near the beginning of the
physical disk. How do I check what is depending on what? It seems it's only
the multi-boot.target that waits for it...

-- 
- Toyam