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.