Re: [gentoo-user] Are those "green" drives any good?

[Paul Hartman <paul.hartman+gentoo@gmail.com>]

On Thu, May 10, 2012 at 6:55 AM,  <napalm@squareownz.org> wrote:
>
> hum hum!
> I know that Windows does this by default (it annoys me so I disable it)
> but does linux disable or stop running the disks if they're inactive?
> I'm assuming there's an option somewhere - maybe just `unmount`!

Some drives cannot have this spindown "feature" disabled, because it
is a fixed value in their firmware in order to be "green"...

You can adjust the power management setting with hdparm, and on some
drives this allows disabling the spindown or disabling power
management altogether.

On my HDDs, I cannot disable APM but I can disable spindown by
changing the power-saving level to 254. I have a script in
/etc/local.d/ which calls:

hdparm -B 254 /dev/sd[abcdef]

at boot time.

To quote the hdparm manpage:

"A low value means aggressive power  management and a high value means
better performance.  Possible settings range from values 1 through 127
(which permit spin-down), and values 128 through 254 (which do not
permit spin-down).  The highest degree of power  management is
attained  with  a setting of 1, and the highest I/O performance with a
setting of 254.  A value of 255 tells hdparm to disable Advanced Power
Management altogether on the drive (not all drives support  disabling
it,  but most do)."