Fedora 10 - Boot Analysis

[Ville Skyttä]

On Wednesday 17 December 2008, Arjan van de Ven wrote:
> On Tue, 16 Dec 2008 17:16:36 -0500 (EST)
>
> Seth Vidal <skvidal at fedoraproject.org> wrote:
> > > Or hibernate?
> >
> > At least on my system hibernate takes as much time as a reboot.
>
> btw this is a very fundamental property of hibernate. You need to do all
> disk IO to get the system state to disk. And then at resume, you need
> to do all disk IO to get the state from disk again. That's twice ;)
>
> This is compounded by the property that a hibernate tends to flush at
> least half the disk cache (it has to, to get space to work in), which
> you then need to page right back in, so even when you're back, the first
> minute or two sucks badly.
>
> I suspect you will always be able to boot faster than you can
> hibernate+resume.

I have very different experience.  For example comparable (from grub going 
away to KDE + my bunch of default apps running and usable) numbers just taken 
from the desktop box in front of which I'm right now (AMD64 3200, 2G RAM, 
SATA, F-9 x86_64 KDE):

- shutdown: 28 sec
- fresh boot: 66 sec
- suspend to disk: 17 sec
- resume from disk: 23 sec

Shutdown takes a ~5 second penalty compared to suspend to disk due to the 
shutdown sound during which everything else appears to be idling, and fresh 
boot takes a bit of a penalty because my most recent readahead-collector run 
(using the F-10 one) is not very recent, but the numbers speak for themselves 
anyway.  Also, I have a gut feeling that the sluggishness for a while after 
the desktop is up is clearly worse on a fresh reboot than in resume from disk 
case.  But it's possible that I misremember this one - I haven't really shut 
down/rebooted except for kernel updates in almost half a year.