K 10
svn:author
V 6
brucec
K 8
svn:date
V 27
2010-10-24T16:31:57.848725Z
K 7
svn:log
V 566
Mostly revert r203420, and add similar functionality into ada(4) since the
existing code caused problems with some SCSI controllers.

A new sysctl kern.cam.ada.spindown_shutdown has been added that controls
whether or not to spin-down disks when shutting down.
Spinning down the disks unloads/parks the heads - this is
much better than removing power when the disk is still
spinning because otherwise an Emergency Unload occurs which may cause damage
to the actuator.

PR:	kern/140752
Submitted by:   olli
Reviewed by:	arundel
Discussed with: mav
MFC after:	2 weeks

END