Re: debian-installer - using devfs in the installed system

[Bdale Garbee <bdale@gag.com>]

waldi@debian.org (Bastian Blank) writes:

> we discuss some time about using devfs in the installed system to avoid
> mapping the devices which may break things. s390 currently uses devfs
> and don't have any problems with it.
> devfs is available after the feature freeze of linux 2.6 so it seems to
> be availble with this version.
>
> i ask this before we make a decision to get some other opinions about
> that.

I just had a brief conversation about this with a couple of my friends who are
closer to the kernel development process than I am.  I've heard mixed things
about devfs in general, and wanted informed opinions.  They made it pretty
clear that while some form of devfs may still exist in 2.6, that it's not
necessarily a robust thing to depend on for debian-installer, and they advised
against using it.

They suggested that code in user space looking at /proc/partitions or even
/proc/devices for hints about what /dev entries to create on the fly outside
the kernel would give us more control over how it works, be robust in the face
of possible kernel devfs functionality changes, etc.  Sounded reasonable to 
me, particularly since I think we'd like debian-installer to work for at least
2.4 and 2.6 kernels, if not well beyond.

While opinions may vary, I wonder if we're really smart to depend on devfs as
a kernel feature for the limited use we need to make of it in the install
process?  Or is there some big win from devfs that I haven't understood yet?

Bdale