mdev with hda's

Harald Becker ralda at
Wed May 11 22:24:10 UTC 2011

 Hallo David!

> Since both are immediately exporting the environment, they will have
> the same information as originally posted, but for the sake of
> argument, I did as asked with the output below:

Click! ... thinking about I found the possible solution why hd devices
show up with a shell inherited environment ...

... the reason is contained in your above statement: hd and sd device do
*not* both *immediately* export the environment ... I assume you are
using a standard kernel, with statically included ata driver ... the
kernel/device startup sequence differes between hd and sd devices. hd
devices are present before init startup and do not produce hotplug
events (as far as I noted). sd devices produce hotplug events on
startup. That leads to the extreme difference of environment setup. hd
devices are setup during initial "mdev -s" run ... and inherit the
calling shells environment, whereas sd devices are initialized by
hotplug events called from scsi kernel threads ... and inherit the
kernel threads environment.

... that will explain all noted differences and behavior ... but may
need some verification (only solved theoretically).

> TERM=linux
> OS=XiniX
> USER=root
> LD_LIBRARY_PATH=/lib:/home/root/.lib:/home/.everyone/.lib
> bootmode=normal
> PATH=/home/root/.etc/defaults:/etc/defaults:/home/root/.bin:/home/root/.sbin:/bin:/sbin
> vga=0x314
> PWD=/dev
> ADMAIL=support at
> HOME=/home/root
> PIDDIR=/var/run/pids
> SVDIR=/var/run/services
> VER=0.5
> ADMIN=Dave

Is this the environment setting of your startup / init script(s)?
Especially the variables vga and bootmode are an indication for this

May be you can search through your init scripts and locate the "mdev -s"
call ... put an "env >/tmp/init_env" there (just before mdev call) and
compare output with above list. Add an "export MDEV_TEST=irgendwas"
bevor the "mdev -s", this shall show up as "MDEV_TEST=irgendwas" in your
mdev output for hda devices ... if I'm right with my above theory.


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