Fwd: Fwd: sg3_utils, sdparm and ddpt

[Matthew Jacob]

-------- Original Message --------
Subject: 	Fwd: sg3_utils, sdparm and ddpt
Date: 	Wed, 27 Oct 2010 10:49:46 -0400
From: 	Douglas Gilbert <dgilbert at interlog.com>
Reply-To: 	dgilbert at interlog.com
To: 	Matthew Jacob <mj at feral.com>



Matthew,
I tried to post the following to the freebsd-scsi
list a week ago. The response said it was going
to be moderated but it has not turned up on the list
yet.

Could you help to get it posted?

Doug Gilbert


-------- Original Message --------
Subject: sg3_utils, sdparm and ddpt
Date: Tue, 19 Oct 2010 12:45:47 +0200
From: Douglas Gilbert<dgilbert at interlog.com>
Reply-To: dgilbert at interlog.com
To: freebsd-scsi at freebsd.org

I maintain various SCSI related tools whose native platform
is Linux. These three packages have ports (i.e. tarballs)
that build on FreeBSD:

sg3_utils:
http://sg.danny.cz/sg/sg3_utils.html

sdparm:
http://sg.danny.cz/sg/sdparm.html

ddpt:
http://sg.danny.cz/sg/ddpt.html

ddpt was released recently and adds SCSI pass-through
support and other extensions to the standard dd command.

In Linux the SCSI pass-through can be applied to (S)ATA
disks since recent Linux kernels "hide" most ATA devices
behind a SAT layer. When I tested on a FreeBSD 8.0
release there was no SAT layer in front of ATA devices
making ddpt's pass-through less useful.
As an example ddpt can be used to "trim" all or part of
a SSD in Linux. Even though most SSDs on the market have
a SATA interface, ddpt can issue a SCSI WRITE SAME
command (with the UNMAP bit set) which the Linux SAT
layer translates into a ATA DATA SET MANAGEMENT command
(with the TRIM bit set).

Doug Gilbert