.TH SG_SCAN "8" "December 2006" "sg3_utils\-1.23" SG3_UTILS .SH NAME sg_scan \- scan scsi devices, volume names, physical drives, cdrom/dvd drives and tapes and show relationships .SH SYNOPSIS .B sg_scan [\fI\-\-help\fR] [\fI\-\-letter=VL\fR] [\fI\-\-verbose\fR] [\fI\-\-version\fR] .SH DESCRIPTION .\" Add any additional description here .PP The purpose of this utility is to show which device names the other utilities in this package will accept. It scans SCSI and various related device types often finding multiple device names. It then attempts to place all the device names for a device on a single line. .PP Storage and related devices can have several device names in Windows. Probably the most common in the volume name (e.g. "D:"). There is also a "class" device name, and this utility scans for three of them: "PhysicalDrive", "CDROM" and "TAPE". is an integer starting at 0 allocated in ascending order as devices are discovered (and sometimes rediscovered). .PP Then there is a lower level device name which starts with a SCSI (pseudo) adapter name of the form "SCSI:". To this is added sub\-addressing in the form of a "bus" number, a "target" identifier and a lun (logical unit number). The "bus" number is also known as a "PathId". These components are combined by the utility to make a device name of the form: "SCSI:,,". This utility allows the trailing "," to be omitted in which case a lun of zero is assumed. This lower level device name cannot often be used directly since Windows blocks attempts to use it if a class driver has "claimed" the device. There are SCSI device types (e.g. processor type) for which there is no class driver. At least two transports: USB and IEEE 1394 do not have a "scsi" device names of this form. .PP In keeping with DOS file system conventions, the various device names can be given in upper, lower or mixed case. Since "PhysicalDrive" is tedious to write, a shortened form of "PD" is permitted by this utility. .PP A single device (e.g. a disk) can have many device names! For example: "PDO" can also be "C:", "D:" and "SCSI0:0,1,0". The two volume names reflect that the disk has two "Windows" partitions on it. .PP So this utility tries to scan the SCSI and related devices, generating one line (sometimes more) of output for each device found. First appears the "scsi" device name or blanks if there is none. Next follows the volume letter (if any) optionally followed by a "+" to indicate more volume letters map to this device. Next is one of the class device names or blanks followed by a concatenation of the INQUIRY response strings. Windows often manufactures INQUIRY response strings for non\-SCSI devices (e.g. a parallel ATA disk at "C:") and doesn't quite obey the SCSI\-2 rules for an INQUIRY response. If this utility sees that it places a "*" after the INQUIRY response strings. .PP In some cases this utility is unable to distinguish that various device names represent the same device (e.g. USB and IEEE 1394 devices). Rather than guess, they appear as two lines (not always adjacent). An educated guess could be made but could be tricked, for example, by two USB sticks with the same model and manufacturer. .PP For more information see the NOTES section below. .SH OPTIONS Arguments to long options are mandatory for short options as well. .TP \fB\-h\fR, \fB\-\-help\fR outputs the usage message summarizing command line options then exits. .TP \fB\-l\fR, \fB\-\-letter\fR=\fIVL\fR normally when a device a multiple volume names (e.g. a disk with two partitions recognized by Windows) then the lowest letter volume name in alphabetical order is output, followed by a "+". Hence subsequent matching volume letters are not shown. If the user is interested in a particular volume name then its letter can be given as the \fIVL\fR argument and if found it will be output rather than the lowest volume name. .TP \fB\-v\fR, \fB\-\-verbose\fR increases the level or verbosity. .TP \fB\-V\fR, \fB\-\-version\fR print out version string .SH NOTES This utility uses the SCSI Pass Through (direct) [SPT] interface rather than Adaptec's ASPI32. ASPI32 requires a dll not distributed with Windows. Using the SPT interface requires that a user has administrative rights. This utility does not support Windows 95, 98 and ME (and earlier Windows operating systems). The target Windows operating systems are currently Windows 2000, 2003 and XP (and their variants). .PP If no class device name is found then "pdt=" is placed at the end of the line. This is the SCSI "peripheral device type" (see SPC\-4 at http://www.t10.org). Some values are: 0 \-> disks, 1 \-> tapes, 3 \-> processor, 5 \-> cd/dvds, 8 \-> medium changers, 13 \-> SES devices. .PP The DOS device names given the the CreateFile() call all start with a "\\.\" string. That can be given but if not will be supplied automatically. For the SCSI lower level interface the adapter name (e.g. "SCSI2:") is given to the CreateFile() call and the sub\-addressing (i.e. bus, target and lun) is given to each SCSI pass through command. .PP Scanning devices that are hot unplugged and replugged often can be problematic, especially with the class device names. Each time a device is removed and re\-added it gets a larger class device name (e.g. "PD3" becomes "PD4" leaving "PD3" unused). This utility stops scanning class devices after it find 8 consecutive "holes". If this turns out to be a problem then adjustments will be made. .SH EXIT STATUS The exit status of sg_scan is 0 when it is successful. Otherwise see the sg3_utils(8) man page. .SH AUTHORS Written by D. Gilbert .SH COPYRIGHT Copyright \(co 2006 Douglas Gilbert .br This software is distributed under a FreeBSD license. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.