The sg3_utils package contains utilities that send SCSI commands to devices.
As well as devices on transports traditionally associated with SCSI (e.g.
Fibre Channel (FCP), Serial Attached SCSI (SAS) and the SCSI Parallel
Interface(SPI)) many other devices use SCSI command sets. It's
functions similar to camcontrol(8), but more powerful. For example,
it can use SCSI Environmental Services not using FreeBSD ses(4), 
read SCSI device logs, and much more. 

WWW: http://sg.torque.net/sg/sg3_utils.html