CH(4)                     OpenBSD Programmer's Manual                    CH(4)

NAME
     ch - scsi media-changer (juke box) driver

SYNOPSIS
     ch? at scsibus?

DESCRIPTION
     The ch driver provides support for SCSI juke boxes.  It allows many slots
     of media to be multiplexed between a number of drives.

     A SCSI adapter and a logical scsibus must also be separately configured
     into the system before a SCSI changer can be configured.

     As the SCSI adapter is probed during boot, the SCSI bus is scanned for
     devices.  Any devices found which answer as "Changer" type devices will
     be ``attached'' to the ch driver.  The first device found will be at-
     tached as ch0 and the next ch1, etc.  It is also possible to specify what
     ch unit a device should come on-line as; refer to scsi(4) for details on
     kernel configuration.

FILES
     /dev/ch[0-9]  device entries

SEE ALSO
     chio(1), cd(4), intro(4), scsi(4), sd(4), st(4)

HISTORY
     The ch driver appeared in 386BSD 0.1.

OpenBSD 4.7                      May 31, 2007                                1
