I recently installed mandrake 9.1 on a newly aquired Toshiba laptop.
The installation went well, but the main problem I have is that Linux
is not very laptop friendly and it makes
the poor hard-drive click far too often, and as a consequence
does not give the disk time to powerdown. This is noticable
when I compare the battery usage between Linux and Win XP -
the latter gives me a much better battery life and less drive clicking.

A bit of web research reveals the potential cause of the problem is
due to three things:

(i) The ext3 journal commit interval (default 5sec)
(ii) the kernal flushing dirty buffers - controlled by the dirty buffer age
(30secs) and how often the update daemon (kupdated) runs (every
5secs).
(iii) File access times being continuously updated.

Now (iii) can be disabled by specifying noatime as a mount option
in /etc/fstab, but in fact mandrake 9.1 had already set this up
as the default.

I understand (i) is controlled by an undocumented mount option
for ext3 (commit=5 for default behaviour) in recent kernels.

(ii) is controlled by some options to /sbin/update (e.g. -f 300
and -s 300 for 5min flushes).

Now /sbin/update is meant to be called early on at boot up and it is
usually found in /etc/inittab (e.g. in RH9.0). But lo-n-behold, the
relevant line

ud:nce:/sbin/update

is not in my mandrake 9.1 inittab file (though it is present in
mandrake 9.0 on my desktop). I can't see it anywhere else in
the initscripts either, so don't see where I can add the options.

Does anyone here have any idea what mandrake has done to the init
scripts/process and where does it start /sbin/update?