[arch-general] Optimizing boot

[Gesh]

On April 30, 2014 1:28:52 PM GMT+03:00, Paul Gideon Dann <pdgiddie at gmail.com> wrote:
>On Wednesday 30 Apr 2014 11:08:14 Mike Cloaked wrote:
>> 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.
>
>Since we're on the topic, does anyone have a clue how I can find out
>why systemd hangs for 
>ages when I shut down or reboot? The display server is shut down, I'm
>placed in a TTY with a 
>"shutting-down" message, but then it looks like it's waiting for
>something that never happens, 
>and then I think I see something flash past about a watchdog timeout
>before it proceeds. If I 
>could get rid of that hanging step, it would save me waiting 60 seconds
>or however long each 
>time I reboot (which is infrequently enough that it's only been a mild
>annoyance so far).
>
>What's the correct way to diagnose this? I don't think systemd-analyze
>can handle 
>shutdown. Could this be an initrd thing?
>
>Paul

I see the same thing on my box.
The system shuts down, I get a message to that effect printed, yet the hardware keeps running for more than 3m. Eventually, I always cold-shutdown the computer when it reaches that state.
Any ideas why this is?
Gesh