NAME

chio — medium changer control utility

SYNOPSIS

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.

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 code, which is 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”.

The following commands are supported:

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/src-EU is moved to dst1-ET/dst1-EU and the media unit previously in dst1-ET/dst1-EU is moved to dst2-ET/dst2-EU. In the case of a simple exchange, dst2-ET/dst2-EU is omitted and the values src-ET/src-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/dst2-EU and dst2-ET/dst2-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.

getpicker

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

move from-ET from-EU to-ET to-EU [inv]

Moves the media unit from from-ET/from-EU to to-ET/to-EU. If the optional modifier inv is specified, the media unit will be inverted before insertion. If from-ET is a drive, chio will first attempt to open and perform an MTOFFL operation on the st(4) device corresponding to from-EU. By default, the st(4) device /dev/rstX is used, where X is the from-EU. This mapping can be changed by using the chio.conf(5) file.

params

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

position to-ET to-EU [inv]

Position the picker in front of the element described by to-ET/to-EU. If the optional modifier inv is specified, the media unit will be inverted before insertion.

Note that not all changers behave as expected in response to this command.

setpicker unit

Configure the changer to use picker unit.

status

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

-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.

-a

Print all additional information (as in -vV).

The status bits output 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.

ENVIRONMENT

CHANGER

The default changer may be overridden by setting this environmental variable to the desired changer device.

FILES

/dev/ch0

Default changer device.

/etc/chio.conf

Optional configuration file to set up a non-default mapping between st(4) devices and changer drives.

EXAMPLES

Move the media in slot 3 (fourth slot) to drive 0 (first drive):

Move the media with volume tag 000007L2 to drive 1 (second drive):

Configure the changer to use picker 2 (third picker) for operations:

SEE ALSO

mt(1), ch(4), st(4), chio.conf(5)

HISTORY

A chio utility appeared in NetBSD 1.3.

AUTHORS

The chio program and SCSI changer driver were written by Jason R. Thorpe <‍thorpej@and.com> for And Communications (http://www.and.com/).