lsscsi, sg3-utils, ddpt, Adaptec USBXchange/USB2Xchange support

Hi,

This post is to suggest some additions to the BackTrack DVD image. At least lsscsi and sg3-utils are available in the repository (i.e. you can apt-get them); I didn't check whether ddpt is available there yet. IMHO these are useful enough to warrant inclusion in the DVD.

lsscsi - http://sg.danny.cz/scsi/lsscsi.html
lsscsi is useful to list all connected SCSI devices (that includes IDE/SATA and USB drives too) and the corresponding SCSI generic device (/dev/sgN). Knowing the SCSI generic device corresponding to a block device is useful for several reasons, e.g. using sg_start (from the sg3-utils package) to spin down a hard disk.

sg3-utils - http://sg.danny.cz/sg/sg3_utils.html
This contains various programs for issuing direct SCSI commands to devices. Useful for data recovery/forensics and more. E.g. sg_start for spinning down a drive. sg_dd is like dd except can perform direct SCSI I/O. (But ddpt is a more recent similar program, see below.) sg_format to issue FORMAT UNIT commands, ...

ddpt - http://sg.danny.cz/sg/ddpt.html
ddpt is a dd-like program, but with some useful extras. It can perform direct SCSI I/O rather than go through the kernel block layer. It can also create an image file sparsely, which can save a huge amount of disk space and time when imaging a disk. You can also easily resume imaging after interrupting part-way through. You can control the size of each I/O request so it's much more efficient than dd for e.g. extracting an arbitrary byte range from a file.

In some cases, the Linux kernel incorrectly "corrects" the size of a block device making the last sector inaccessible. That's not good for disk imaging/forensic purposes. Using sg_dd or ddpt you can image the entire drive using direct SCSI I/O, bypassing the block layer problem.

The Adaptec USBXchange and USB2Xchange are SCSI<->USB converters, very useful for accessing data on legacy parallel SCSI drives connected to a modern computer's USB port. In order for them to work in Linux, firmware for them would need to be included. A kernel patch for these was given here.