[arch-general] Optimizing boot

[Mike Cloaked]

On Wed, Apr 30, 2014 at 10:56 AM, Toyam Cox <csupercomputergeek at gmail.com>wrote:

>
> Startup finished in 4.215s (firmware) + 176ms (loader) + 2.939s (kernel) +
> 11.166s (userspace) = 18.497s
>
> Thank you very much! NetworkManager takes a much more reasonable 1.4
> seconds now. It would not have occured to me to have the journal checked. I
> also enabled readahead, and now LXDE starts before I'm finished booting, a
> very nice feature.


Just a comment about boot times. The overall boot performance will depend
not only on optimising an individual setup, but also is dependent on the
hardware as well as which boot manager is being used.  So an older laptop
with a hard drive, using BIOS boot and optimised will still see much longer
boot time than say a new laptop running a fast i7 processor, with an ssd,
using UEFI and also optimised.  Certainly I have an old laptop that takes
around 35 seconds to boot to the login prompt from when the boot manager
takes over after POST using BIOS legacy boot, but a similarly set up and
optimised new Haswell i7 laptop, with msata ssd using refind for UEFI boot
takes about 7 seconds to reach the KDM login prompt. Of course for a
specific system it may be possible to shave some seconds off the boot time,
but it will also depend on which server daemons need to be started as well.
So adding dovecot, an MTA, and maybe a DHCP server all add to the time
taken to complete the boot process.

So comparisons of absolute boot times from different machines are difficult
to interpret.

-- 
mike c