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 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''.

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 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 command.

     params  Report the number of slots, drives, pickers, and portals in the changer, and which picker unit the changer is currently configured 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 timeout in
	     seconds for the operations.  This may be used if the operation 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 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 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 operations.

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