SG_SCAN(8)							     SG3_UTILS								SG_SCAN(8)

NAME

       sg_scan - scans sg devices (or SCSI/ATAPI/ATA devices) and prints results

SYNOPSIS

       sg_scan [-a] [-i] [-n] [-w] [-x] [DEVICE]*

DESCRIPTION

       If  no DEVICE names are given, sg_scan does a scan of the sg devices and outputs a line of information for each sg device that is currently
       bound to a SCSI device. If one or more DEVICEs are given only those devices are scanned.  Each device is opened with the O_NONBLOCK flag so
       that the scan will not "hang" on any device that another process holds an O_EXCL lock on.

       Any  given  DEVICE name is expected to comply with (to some extent) the Storage Architecture Model (SAM see www.t10.org).  Any device names
       associated with the Linux SCSI subsystem (e.g. /dev/sda and /dev/st0m) are suitable. Devices names associated with ATAPI devices (e.g. most
       CD/DVD drives and ATAPI tape drives) are also suitable.	If the device does not fall into the above categories then an ATA IDENTIFY command
       is tried.

       In Linux 2.6 and 3 series kernels, the lsscsi utility may be helpful. Apart from providing more information (by data-mining  in	the  sysfs
       pseudo file system), it does not need root permissions to execute, as this utility would typically need.

OPTIONS

       -a     do alphabetical scan (i.e. sga, sgb, sgc). Note that sg device nodes with an alphabetical index have been deprecated since the Linux
	      kernel 2.2 series.

       -i     do a SCSI INQUIRY, output results in a second (indented) line. If the device is an ATA disk then	output	information  from  an  ATA
	      IDENTIFY command

       -n     do numeric scan (i.e. sg0, sg1...) [default]

       -w     use a read/write flag when opening sg device (default is read-only)

       -x     extra information output about queuing

NOTES

       This  utility  was  written  at	a  time when hotplugging of SCSI devices was not supported in Linux. It used a simple algorithm to scan sg
       device nodes in ascending numeric or alphabetical order, stopping after there were 4 consecutive errors.

       In the Linux kernel 2.6 series, this utility uses sysfs to find which sg device nodes are active and only checks those. Hence there can	be
       large  "holes"  in  the	numbering of sg device nodes (e.g. after an adapter has been removed) and still all active sg device nodes will be
       listed. This utility assumes that sg device nodes are named using the normal conventions and searches from /dev/sg0 to  /dev/sg4095  inclu-
       sive.

EXIT STATUS

       The exit status of sg_scan is 0 when it is successful. Otherwise see the sg3_utils(8) man page.

AUTHORS

       Written by D. Gilbert and F. Jansen

COPYRIGHT

       Copyright (C) 1999-2013 Douglas Gilbert
       This  software  is distributed under the GPL version 2. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR-
       POSE.

SEE ALSO

       lsscsi(8)

sg3_utils-1.36							     May 2013								SG_SCAN(8)