Re: [D-I] Supporting 2.6.14 kernels in base-installer

[Sven Luther <sven.luther@wanadoo.fr>]

On Sun, Nov 13, 2005 at 03:22:42PM -0500, Jeff Bailey wrote:
> On dim, 2005-11-13 at 20:34 +0100, Frans Pop wrote:
> > On Sunday 13 November 2005 18:32, Jeff Bailey wrote:
> > > On dim, 2005-11-13 at 12:46 +0100, Bastian Blank wrote:
> > > > I think it is possible at least for initramfs-tools to run without
> > > > sysfs on the building system.
> > >
> > > Right.  The caveat to this is "dep" mode.  The default mode for
> > > initramfs-tools is to include all of the modules that you're likely
> > > interested in booting with in the initramfs and detecting which ones to
> > > use at boot time.  If you ask it to detect which modules are needed, it
> > > needs a valid sysfs tree to scan (although it is resiliant in that case
> > > against module name changes)
> > 
> > Thanks for the explanation.
> > 
> > I think the "dep" mode is to be preferred over the "most" mode in 
> > principle, so this would need to be configured by d-i.
> > I very much doubt that mounting /sys in the chroot will be a problem. It 
> > has worked for me so far when installing 2.6.14 kernels in a chroot.
> 
> FWIW, Ubuntu's install defaults to 'most' mode on the grounds that for
> most systems (not lowmem, not oldworld ppc, not netboot) there's no harm
> in having a larger initramfs (approx 5 meg on disk, 40meg in memory).

A bit over 7MB on powerpc, i think.

> The upside is that the initramfs created should be more or less
> identical for every system and is resilient against people moving the
> drive from one machine to the other, doing perfect copies (using ghost,
> dd, or whatnot), or using an already generated initramfs to recover
> broken systems on other machines.
> 
> I'd argue for keeping that mode as default if possible because there
> isn't any benefit to the smaller initramfs in 95% of cases, and it
> increases the risk of a non-booting system.

I wonder about one thing though, since this is basically a ramdisk, once the
boot is over, what happens to the memory used to hold it ? 

Friendly,

Sven Luther