[ltp] hdparm & spindown time : still having problems

[Noah Dain]

On 12/14/05, Jiang Qian <qian2@fas.harvard.edu> wrote:
> On Thu, Dec 15, 2005 at 02:11:01AM +0000, Paul RIVIER wrote:
> > Hi there,
> >
> > I investigated more about this problem, and I discovered something rell=
y
> > interesting.
> > At least on my system :
> >
> > experiments done with laptop mode activated
> >
> > hdparm -B [1-256] /dev/hda  wont change any visible behaviour.
> > hdparm -S t /dev/hda :
> >
> > Actually, disk will not spindown after t seconds of inactivity.
> >
> > BUT !!!!
> > If I set -B 256, after *exactly t* seconds it will park the heads !
> > If I sec -B (value<256), it will park the head as well, but sooner (whe=
n ?).
> >
> I'm really confused. What do you mean? Do you mean if you do
> hdparm -B [1-256] /dev/hda
> and
> hdparm -S t /dev/hda
> nothing happen but after that two steps *then* if you do
> hdparm -B 256
> after *t * second it spin down?
> So what I need is hdparm -B 256 then hdparm -S t then hdparm -B 256?
> Maybe I'm being dense but your email really confuse me.
> Thanks in advance for clarification.
> Jiang
>
>
> > In any case, hdparm -y will work until next IO call.
> >
> > Any idea ?
> >
> >
> > Paul
> > --

does noflushd spin down your drives?  if so, it should at least
provide a workaround.

to help keep them spun down, there is this reply by Tino Keitel to
another thread in the list:

// start quote

I don't use laptop-mode at all, but use this way to get acceptable
spin down times:

mount -o remount,commit=3D20000 /
mount -o remount,commit=3D20000 /boot
mount -o remount,commit=3D20000 /usr
mount -o remount,commit=3D20000 /var
mount -o remount,commit=3D20000 /home
/etc/init.d/noflushd start

Of couse, you should adjust this to your file systems.

I use kernel 2.6.14 and ext3, and this setup gives me spin down times
up to a few hours. Maybe mounting with noatime could improve this, but
I don't want to criple my system just to get a little bit more battery
lifetime.

Regards,
Tino

// end quote


part of this coming weekend is slated for moving my filesystems to ext3.

--
Noah Dain