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       sg_scan  -  does a scan of sg devices (or given SCSI/ATAPI/ATA devices)
       and prints the results


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


       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   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


       -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

       -x     extra information output about queuing


       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.


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


       Written by D. Gilbert and F. Jansen


       Copyright © 1999-2006 Douglas Gilbert
       This software is distributed under the  GPL  version  2.  There  is  NO
       warranty;  not  even  for  MERCHANTABILITY  or FITNESS FOR A PARTICULAR