laptop hard disk etiquette

[Pádraig Brady]

Pádraig Brady wrote:
> Pádraig Brady wrote:
> 
> 1. ubuntu dicks with the drive spin down timers when on battery

I've heard that by default ubuntu does not mess with these timers,
but will if one sets laptop-mode in /etc/default/acpi-support, anyway...

> 2. fedora does not (as Bill suggested)
> 3. fedora should probably not (as Alan suggested)
> 4. fedora should probably default to relatime mount option
>    on laptops at least (as Ingo suggested here:
>    http://kerneltrap.org/node/14148 )

As Jeff points out F8 will have relatime configured on
by default for all mounts. Yay for sensible defaults!

> Noting that this laptop was running FC4 for most of its life,
> and that it has the following defaults:
> # hdparm -I /dev/sda | grep "Advanced power management level"
>         Advanced power management level: 128 (0x80)
> Using the smart Power_On_Hours value, shows that in total
> it has load cycled on average once every 48s:
> # echo "scale=2; (4718*60*60)/351675" | bc
> 48.29
> 
> That's far too aggressive, especially considering this
> laptop is plugged in most of the time.
> But also note that atime updates were enabled (as per default),
> which probably exacerbated the problem.
> I'll disable that first on all partitions and if that
> doesn't suffice I'll make the "unloading" less agressive
> using the `hdparam -B $level /dev/sda` command.

Disabling atime manually on F7, gets my hard disk
[un]load cycle frequency to decrease from once every 48s
to once every 108s:

$ echo "((4765-4718)*60*60)/(353361-351795)" | bc
108

That's around what I think it should be as a limit,
so can we add "anti hard drive ware technology"
to the new features in the F8 release notes :)

I did also notice a bug which mentions that this
issue may be triggered by changes in kernel 2.6.10?
https://bugzilla.redhat.com/show_bug.cgi?id=146628

cheers,
Pádraig.