K 10
svn:author
V 6
brucec
K 8
svn:date
V 27
2010-11-12T11:22:59.132340Z
K 7
svn:log
V 712
MFC r214279:

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.

The FLUSH_CACHE + STANDBY_IMMEDIATE commands are issued following the
procedure documented in Fujitsu's MHW series product documentation under
section 1.10.1, "Recommended power-off sequence".

PR:	kern/140752
Submitted by: olli

END