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CHIO(1)                 FreeBSD General Commands Manual                CHIO(1)

     chio - medium changer control utility

     chio [-f changer] command [-<flags>] arg1 arg2 [arg3 [...]]

     The chio utility is used to control the operation of medium changers,
     such as those found in tape and optical disk jukeboxes.

     The options are as follows:

     -f changer
             Use the device changer rather than the default device /dev/ch0.

     The default changer may be overridden by setting the environment variable
     CHANGER to the desired changer device.

     A medium changer apparatus is made up of elements.  There are five
     element types: picker (medium transport), slot (storage), portal
     (import/export), drive (data transfer), and voltag (select by volume
     identifier).  The voltag pseudo-element type allows the selection of
     tapes by their volume tag (typically a barcode on the tape).

     In this command description, the shorthand ET will be used to represent
     an element type, and EU will be used to represent an element unit.  For
     example, to represent the first robotic arm in the changer, the ET would
     be ``picker'' and the EU would be ``0''.

     move _from ET_ _from EU_ _to ET_ _to EU_ [inv]
             Move the media unit from _from ET/EU_ to _to ET/EU_.  If the
             optional modifier inv is specified, the media unit will be
             inverted before insertion.

     exchange _src ET_ _src EU_ _dst1 ET_ _dst1 EU_ [_dst2 ET_ _dst2 ET_]
             [inv1] [inv2]
             Perform a media unit exchange operation.  The media unit in _src
             ET/EU_ is moved to _dst1 ET/EU_ and the media unit previously in
             _dst1 ET/EU_ is moved to _dst2 ET/EU_.  In the case of a simple
             exchange, _dst2 ET/EU_ is omitted and the values _src ET/EU_ are
             used in their place.  The optional modifiers inv1 and inv2
             specify whether the media units are to be inverted before
             insertion into _dst1 ET/EU_ and _dst2 ET/EU_ respectively.

             Note that not all medium changers support the exchange operation;
             the changer must have multiple free pickers or emulate multiple
             free pickers with transient storage.

     return _from ET_ _from EU_
             Return the media unit to its source element.  This command will
             query the status of the specified media unit, and will move it to
             the element specified in its source attribute.  This is a
             convenient way to return media from a drive or portal to its
             previous element in the changer.

     position _to ET_ _to EU_ [inv]
             Position the picker in front of the element described by _to
             ET/EU_.  If the optional modifier inv is specified, the media
             unit will be inverted before insertion.

             Note that not all changers behave as expected when issued this

     params  Report the number of slots, drives, pickers, and portals in the
             changer, and which picker unit the changer is currently
             configured to use.

             Report which picker unit the changer is currently configured to

     setpicker _unit_
             Configure the changer to use picker _unit_.

     ielem [_timeout_]
             Perform an INITIALIZE ELEMENT STATUS operation on the changer.
             The optional _timeout_ parameter may be given to specify a
             timeout in seconds for the operations.  This may be used if the
             operation takes unusually long because of buggy firmware or the

     voltag [-fca] _ET_ _EU_ [_label_] [_serial_]
             Change volume tag for an element in the media changer.  This
             command is only supported by few media changers.  If it is not
             supported by a device, using this command will usually result in
             an "Invalid Field in CDB" error message on the console.

             If the -c flag is specified, the volume tag of the specified
             element is cleared.  If the -f flag is specified, the volume tag
             is superseded with the specified volume tag even if a volume tag
             is already defined for the element.  It is an error to not
             specify the -f flag when trying to set a label for an element
             which already has volume tag information defined.

             The command works with the primary volume tag or, if the -a flag
             is given, with the alternate volume tag.

     status [-vVsSbIa] [_type_]
             Report the status of all elements in the changer.  If _type_ is
             specified, report the status of all elements of type _type_.

     -v      Print the primary volume tag for each loaded medium, if any.  The
             volume tag is printed as ``<LABEL:SERIAL>''.

     -V      Print the alternate volume tag for each loaded medium, if any.

     -s      Print the additional sense code and additional sense code
             qualifier for each element.

     -S      Print the element source address for each element.

     -b      Print SCSI bus information for each element.  Note that this
             information is valid only for drives.

     -I      Print the internal element addresses for each element.  The
             internal element address is not normally used with this driver.
             It is reported for diagnostic purposes only.

     -a      Print all additional information (as in -vVsSba).

     The status bits are defined as follows:

     FULL    Element contains a media unit.

     IMPEXP  Media was deposited into element by an outside human operator.

     EXCEPT  Element is in an abnormal state.

     ACCESS  Media in this element is accessible by a picker.

     EXENAB  Element supports passing media (exporting) to an outside human

     INENAB  Element supports receiving media (importing) from an outside
             human operator.

     /dev/ch0  default changer device

     chio move slot 3 drive 0
             Move the media in slot 3 (fourth slot) to drive 0 (first drive).

     chio move voltag VOLUME01 drive 0
             Move the media with the barcode VOLUME01 to drive 0 (first

     chio return drive 0
             Remove the tape from drive 0 (first drive) and return it to its
             original location in the rack.

     chio setpicker 2
             Configure the changer to use picker 2 (third picker) for

     mt(1), mount(8)

     The chio program and SCSI changer driver were written by Jason R. Thorpe
     <> for And Communications,

     Additional work by Hans Huebner <> and Steve Gunn

FreeBSD 11.0-PRERELEASE          May 14, 1998          FreeBSD 11.0-PRERELEASE


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