CHIO(1)                    OpenBSD Reference Manual                    CHIO(1)

NAME
     chio - medium changer control utility

SYNOPSIS
     chio [-f changer] command 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 four element
     types: picker (medium transport), slot (storage), portal (import/export),
     and drive (data transfer).  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
     chio move <from ET> <from EU> <to ET> <to EU> [inv]

     Moves 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 inser-
     tion.

     chio exchange <src ET> <src EU> <dst1 ET> <dst1 EU> [<dst2 ET> <dst2 EU>]
     [inv1] [inv2]

     Performs 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 invert-
     ed 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.

     chio 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.

     chio params

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

     chio getpicker

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

     chio setpicker <unit>

     Configure the changer to use picker <unit>.

     chio status [<type>]

     Report the status of all elements in the changer.  If <type> is speci-
     fied, report the status of all elements of type <type>.

     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 hu-
             man operator.

EXAMPLES
     chio move slot 3 drive 0

     Moves the media in slot 3 (fourth slot) to drive 0 (first drive).

     chio setpicker 2

     Configures the changer to use picker 2 (third picker) for operations.

FILES
     /dev/ch0  default changer device

SEE ALSO
     mt(1), ch(4), 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/).

OpenBSD 2.9                      April 2, 1996                               2
