Laptop mode and SCSI disks

[W. Michael Petullo]

I am interested in using the kernel's laptop mode to reduce the power
usage of a server.  The server has an external IEEE 1394 drive that could
easily be spun down for large periods of time.  The IEEE 1394 drive is,
of course, treated as a SCSI disk by the kernel.

I have found that spinning down SCSI disks is not as easy as spinning
down IDE disks.  I have found utilities to do this, but they require
kernel patches and these patches do not seem to exist for the 2.6 kernel's
SCSI sub-system.  Scsi-spin, scsi-idle and noflushd are some of the
options I've looked at.

Is anyone working on automatically spinning down SCSI (including USB
and IEEE 1394) disks?  Would it be worthwhile for me to try and port
the 2.4 "spindown ioctl" patch to 2.6?  Or does similar functionality
already exist in 2.6?

I also have some questions about laptop mode specifically: Is there
something "magical" that causes disks to spin down after a certain
inactivity period when laptop mode is enabled?  Or does "hdparm -S X"
still need to be used to set this?

"hdparm -S 1 /dev/sda" currently says:

/dev/sda:
 setting standby to 1 (5 seconds)
 HDIO_DRIVE_CMD(setidle1) failed: Invalid argument

would hdparm also need to be patched to support SCSI disks?

-- 
Mike

:wq