CHIO(1) 		  BSD General Commands Manual		       CHIO(1)

NAME
     chio — medium changer control utility

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

DESCRIPTION
     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 ele‐
     ment 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”.

SUPPORTED COMMANDS
     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 spec‐
	     ify 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 conve‐
	     nient 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
	     command.

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

     getpicker
	     Report which picker unit the changer is currently configured to
	     use.

     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 time‐
	     out in seconds for the operations.  This may be used if the oper‐
	     ation takes unusually long because of buggy firmware or the like.

     voltag [-fca] <ET> <EU> [<label>] [<serial>]
	     Change volume tag for an element in the media changer.  This com‐
	     mand is only supported by few media changers.  If it is not sup‐
	     ported 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 ele‐
	     ment 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 quali‐
	     fier 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
	     operator.

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

FILES
     /dev/ch0  default changer device

EXAMPLES
     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
	     drive).

     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 opera‐
	     tions.

SEE ALSO
     mt(1), mount(8)

AUTHORS
     The chio program and SCSI changer driver were written by Jason R. Thorpe
     ⟨thorpej@and.com⟩ for And Communications, http://www.and.com/.

     Additional work by Hans Huebner ⟨hans@artcom.de⟩ and Steve Gunn
     ⟨csg@waterspout.com⟩.

BSD				 May 14, 1998				   BSD