xenial (8) sg_scan.8.gz

Provided by: sg3-utils_1.40-0ubuntu1_amd64 bug

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 queueing


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 inclusive.


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 © 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 PURPOSE.


SEE ALSO
       lsscsi(8)