i586 kernels [Was: very common kernel modules slow down the boot process]

[Ralf Corsepius]

On Tue, 2008-04-08 at 09:30 +0200, Gianluca Sforna wrote:
> On Thu, Apr 3, 2008 at 4:18 PM, Ralf Corsepius <rc040203 at freenet.de> wrote:
> >  Actually, my old i586 system works quite smoothly with FC8 and better it
> >  did with some older Fedoras.
> >
> 
> Last time I tried (around FC6) I was not able to use Fedora for one
> little i586 class box¹ I have around due to the absence of a
> corresponding kernel.
I've been hit by this bug myself ca. during the FC6/FC7 time-frame.
AFAICT, the cause had been a bug somewhere in installer , which had
caused installing on i586 to install the wrong (i686) kernel.

[User visible symptoms had been the installer installing i686 packages,
and using some i686 tls glibc stuff - There is a BZ somewhere.
AFAICT, this is fixed in FC8.]

> Did something change
Yes, plenty has changed between FC6 and FC8.

Noteworthy: 
* FC8 yum uses much less memory than its predecessors.
* This silly installer-bug finally has been fixed.
* Packaging is more granular.
* rpm has been improved (FC6's rpm/yum occasionally killed the rpmdb)

Other tricks I am applying:
* selinux=0 - The amount of memory SELinux uses, causes kernel-OOMs
early while booting.
* sufficient swap - My i586 uses 128MB (2xRAM, inherited from this
machine's past). More swap probably is advisable.
* boot into runlevel 3 (way less memory consuming than runlevel 5).
Switch off everything you don't really need (e.g. rhgb, usb,
NetworkManager, PulseAudio, avahi, etc.).
* Disable yum-updatesd - I update this machine by manually running yum,
occasionally running selective updates (Occasionally, update-floods tend
to cause OOMs).
* Slim down the static installation (number of packages) and dynamic
installation (daemons/services) to your personal "required" minimum.
Fedora's default configuration is pretty generous.

>  (e.g. the i586 variant is built again)
AFAICT, it has always been built.

>  or am I missing something else?
Bring along a lot of time ... installation/updates are really slow ;)

Ralf