Summary: Re: Spin down HDD after disk sync or before power off

[Alexander Best]

On Thu Oct 21 10, Alexander Best wrote:
> On Thu Oct 21 10, Bruce Cran wrote:
> > On Thu, 21 Oct 2010 14:33:49 +0200
> > Dag-Erling Smørgrav <des at des.no> wrote:
> > 
> > > The problem with setting a short idle timeout is that, on a typical
> > > laptop or desktop system, you end up spinning the disk down and back
> > > up several hundred times a day, which increases power consumption, I/O
> > > latency and wear.
> > 
> > Do we think our users are silly enough to set a short timeout of just a
> > few minutes?  I'd think most would use a setting of 20-30 minutes at
> > a minimum. I never did understand why there were so many warnings;
> > after all, some laptops even come with a default APM scheme in their
> > HDDs that powers the disk down after 7 seconds!
> 
> personally i still think something like the attached patch would be nice to
> have. there's a chance users might type the following:
> 
> 'atacontrol spindown device 10'
> 
> thinking the timeout value is measured in minutes. although this gets mentioned
> in atacontrol(4) it might still be worth reminding the user that he/she is
> performing actions which could damage the hardware.

i just stumbled upon PR 144770, where a somebody seems to have mistaken the
spindown value for minutes instead of seconds. so i really think we should have
this warning in atacontrol!

+1 from brucec, if i understood him correctly.

another possibility would be of course changing the spindown value from seconds
to minutes. imo this seems very reasonable, because measuring spindown time in
seconds is too fine grained and not intuitive. just like specifying the
'shutdown -p XX' delay in microseconds would not be useful. ;)

cheers.
alex

> 
> cheers.
> alex
> 
> > 
> > -- 
> > Bruce Cran
> 
> -- 
> a13x

> diff --git a/sbin/atacontrol/atacontrol.c b/sbin/atacontrol/atacontrol.c
> index 4354ddf..75a131a 100644
> --- a/sbin/atacontrol/atacontrol.c
> +++ b/sbin/atacontrol/atacontrol.c
> @@ -317,6 +317,10 @@ ata_spindown(int fd, const char *dev, const char *arg)
>  
>  	if (arg != NULL) {
>  		tmo = strtoul(arg, NULL, 0);
> +		if (tmo < 600)
> +			warnx("setting spindown timeout below 10 minutes is \
> +			      not recommended (see EXAMPLES section of \
> +			      atacontrol(8))\n");
>  		if (ioctl(fd, IOCATASSPINDOWN, &tmo) < 0)
>  			err(1, "ioctl(IOCATASSPINDOWN)");
>  	} else {


-- 
a13x