Comment 242 for bug 59695

Mark Thomas wrote:
> The Debian update is the workaround not the fix:
>
> * Set hdparm power management to 254 for all hard drives.
>
> I'd be happier to see the known idle-writers fixed first, so we can
> start finding out what else causes the problem. I'm concerned that with
> a workaround in place this will get neglected and we'll end up just
> using more power.

Please don't do this!

Here's the reason: it doesn't solve the problem for everybody. The set
of "known idle-writers" are just a subset of the set of "all
idle-writers". Fixing all *known* idle-writers (and then only in the
situations *known to be a problem*) will not fix *anything* for people
using just *any* program in the set "all idle-writers" minus "known
idle-writers". If you miss even *one* program in *one* possible uncommon
configuration or use case it might destroy somebody's hard drive.

Even if you fix *every* program delivered with Ubuntu, in *every*
possible configuration, I will be able to unwittingly write my own very
simple program that contains no bugs at all (it works perfectly), and it
will destroy my hard drive without me noticing it -- all it has to do is
write to disk every 30 seconds or so. Here is a perfectly harmless example:

#! /bin/sh
while true; do
   sleep 30
   (date ; uptime) >> load.log
done

This (untested) program logs my load averages (and uptime) every thirty
seconds. Using the default Ubuntu settings, it will kill the drive, even
if all known idle-writers are fixed.

Simply put: if an OS that allows unprivileged programs to *knowingly*
destroy hardware is not acceptable, then an OS that causes bug-free
programs to destroy hardware *without even knowing it* is not acceptable
either. So, either return an error to the user program
(-EIOTOOOFTENWHILEBEINGSPACEDABOUT30SECONDSAPARTASWELL :-) ) or fix the
problem: protect the hardware, regardless of what unprivileged programs
do. This is what the -B 254 fix does, and it does it well.

About your worry that the other programs may not get fixed: tough.
That's an internal organisational issue that users should not be
bothered with. If you're willing to fix an internal organisational issue
(not being able to push a set of fixes that the organisation deems
necessary) by putting all users' hard drives at risk,
then you're being totally reckless IMNSHO. Not to mention that it won't
actually help, because everybody who could be interested in changing
these programs (i.e., the Ubuntu contributors community) has already
applied the -B 254 workaround by now. In the end the end users will be
the only people without the workaround in place, and if you don't put it
in place for them, they will suffer.

Cheers,
Bart