changers(8)                                                             changers(8)

NAME

       changers - list SCSI autochangers attached to the system


SYNOPSIS

       changers [ -dpv ] [ -a b.t.l | -f filename ] [ -l ]


DESCRIPTION

       The  changers  program  lists  all of the SCSI autochangers (jukeboxes)
       connected to the current system.


OPTIONS

       -a b.t.l
              Selects a specific ordinal SCSI address, where b is the  logical
              SCSI  bus,  t is the SCSI target, and l is the SCSI logical unit
              number (LUN) on that target. See libscsi(8).
       -f filename
	      Specifies an explicit device file name for changers to use on
	      platforms that support direct use  of  device  file names
	      for  jukeboxes.
	      At this time those platforms are Solaris 10+, AIX and Linux.


       -d     Determines the names and addresses of  the  autochanger's  media
              elements (for example, tape drives).

       -l     Performs a complete LUN search for all SCSI adapters in the sys-
              tem.  This argument is accepted on all  systems,  but  does  not
              have  any  effect  on  HP-UX systems.  Due to the method used to
              scan for available devices  on  HP-UX  systems,  all  accessible
              devices  are  always  shown, and the -l option has no additional
              effect.  On all other platforms, the normal behavior is to start
              checking  at  LUN 0 for SCSI devices.  The first empty LUN found
              will end the search for a given target ID.  With the -l  option,
              all  LUN  present  on  all target IDs for all SCSI busses in the
              system will be checked for devices.  This can take a  very  long
              time  and  should  therefore  only  be used when necessary.  For
              example, a Fibre Channel adapter can  support  126  target  IDs,
              each  of  which  may have 80 or more LUNs.  Checking all LUNs on
              this single adapter may take over 10 minutes.
              
       -p     Tells changers to use persistent device names for	 jukeboxes  on
	      platforms	 where	persistent names are supported. Currently only
	      linux has such support.
              
       -v     Lists more detailed  information  about  each  autochanger.  The
              details  indicate  how  many  media transports (MT, for example,
              robot  arm),  storage  transports  (ST,  for   example,   slot),
              import/export  elements  (IE,  for example, mail slot), and data
              transport (DT) elements the autochanger contains. The -v  option
              also provides information about the element movement matrix sup-
              ported by the autochanger.


EXAMPLE

       Sample output is shown below: hal$ changers -dv -a 0.2.0
       scsidev@0.2.0:Vendor <SPECTRA>, Product <4000>
        Data Transfer Element at address 80 is scsidev@0.5.0
               Device:Vendor <HP>, Product <C1533A>
                 Type:Tape
          System Name: /dev/rmt2.1
        Data Transfer Element at address 81 is scsidev@0.6.0
               Device:Vendor <HP>, Product <C1533A>
                 Type:Tape
          System Name: /dev/rmt3.1

                1 MT Element  starting at address 79
               60 ST Elements starting at address 1
                1 IE Element  starting at address 0
                2 DT Elements starting at address 80

                         Element Movement Matrix

                         ->DT,  ->IE,  ->ST,  ->MT
                       MT->DT,MT->IE,MT->ST,______
                       ST->DT,ST->IE,ST->ST,ST->MT
                       IE->DT,______,IE->ST,IE->MT
                       DT->DT,DT->IE,DT->ST,DT->MT
                       ______,______,______,______
                       ______,______,______,______
                       ______,______,______,______
                       ______,______,______,______

SEE ALSO

	libscsi(8)

NetWorker 7.6.2			 Jul 14, 11			 changers(8)