> hdparm 4.1:
> I have a modern 120GB IDE drive that is used only as a backup, and
> would like to put it to sleep during the day. easy, right?
> hdparm -Y /dev/hdb
> unfortunately, this decided to also turn off the DMA support and other
> tuning in /dev/hda !?! this seems a bit absurd to me. did I err
> more importantly, when it is time to wake up the drive,
> * can I check whether the drive is asleep?
> * is there a nice way to wake up an IDE drive?
You should be using a lower case 'y' for your operation. I believe -S will
set the amount of time before the drive will spin down, rather than
implicitly calling it. -C checks the status of the drive.
Most of this information is in : man hdparm
From man hdparm: -Y Force an IDE drive to immediately enter the
lowest power con-
sumption sleep mode, causing it to shut down completely. A
or soft reset is required before the drive can be accessed
(the Linux IDE driver will automatically handle issuing a
if/when needed). The current power mode status can be
using the -C flag.
Notice that it specifies a soft/hard reset is required to reaccess the drive
for "Y" vs. "y".