Re: ata: printf on every spinup/spindown?

On Mon, 16 Mar 2009 20:02:58 +0000
"Poul-Henning Kamp" <phk_at_phk.freebsd.dk> wrote:

> In message <49BE7C5A.2080103_at_icyb.net.ua>, Andriy Gapon writes:
> 
> >I am playing with ata spindown feature and I think that it is really
> >unnecessary to print a message each time ata driver is going to
> >spindown a disk or let it be spinned up:
> >ad6: Idle, spin down
> >ad6: request while spun down, starting.
> >ad6: drive spun down.
> >ad6: Idle, spin down
> >ad6: request while spun down, starting.
> 
> The reason I added the printf was to make it very annoying.
> 
> Spinning a disk up and down too often wears it out much faster than
> leaving it running.
> 
> In general you do not want to spin a disk down unless it is going to
> stay spun down for at least 15-30 minutes.
> 
> If dmesg is going to spin your disk up, then it will wake up every 5
> minutes due to the atrun message and you are clearly doing it wrong.
> 

Related to this, the ATA driver should probably have some means, either
automatically or via atacontrol, of setting the APM value on disks; I
bought a new laptop and immediately had to install
sysutils/ataidle in order to stop the heads loading/unloading several
times per minute by setting APM to 254.  Apparently it's fairly common
for laptop drives to have overly aggressive power settings that need
intervention from the OS.

-- 
Bruce Cran