Boot speedup with readahead

[Jeremy Katz]

On Mon, 2008-09-08 at 11:12 -0400, Seth Vidal wrote:
> On Mon, 2008-09-08 at 18:07 +0300, Panu Matilainen wrote:
> > On Mon, 8 Sep 2008, Harald Hoyer wrote:
> > > Eric Sandeen schrieb:
> > >> Harald Hoyer wrote:
> > >>> Eric Sandeen schrieb:
> > >>>> So when / how often does readahead-collector run now?
> > >>>> 
> > >>>> Thanks,
> > >>>> -Eric
> > >>> Every month.
> > >>> 
> > >>> /etc/cron.monthly/readahead-monthly.cron
> > >> 
> > >> It'd be interesting to do a daily yum update / reboot and see how the
> > >> boot times look, graphed for a couple months.
> > >> 
> > >> Will things degrade until the next collection run?  I wonder if some
> > >> inotify magic might be interesting; if more than X% of the
> > >> previously-collected files have changed, then kick the collector on again?
> > >> 
> > >> -Eric
> > >> 
> > >
> > > hehe, yes, but how would you implement that? :) I don't think this is doable 
> > > :)
> > 
> > A yum-readahead plugin could look at the readahead list after an upgrade 
> > and calculate if refreshing is needed.
> > 
> > /me ducks and hides
> 
> it'd be like 10 lines long.

And doing it this way would be more effective than cron as there are
plenty of people (especially with laptops/desktops which aren't on all
the time) for whom cron really isn't appropriate for anything that we
actually care to have done

Jeremy