*nix Documentation Project
·  Home
 +   man pages
·  Linux HOWTOs
·  FreeBSD Tips
·  *niX Forums

  man pages->OpenBSD man pages -> ch (4)              



NAME    [Toc]    [Back]

     ch - scsi media-changer (juke box) driver

SYNOPSIS    [Toc]    [Back]

     ch? at scsibus? target ? lun ?

DESCRIPTION    [Toc]    [Back]

     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
     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 attached
 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.


     In  configuring, if an optional count is given in the specification, that
     number of SCSI media changers are configured.  Most  storage
for them is
     allocated  only  when  found so a large number of configured
devices is
     cheap (once the first has included the driver).

IOCTLS    [Toc]    [Back]

     The following ioctl(2) call applies to the changer.   It  is
defined in the
     header file <sys/chio.h>.

     CHIOOP      This appears to be a ``do-everything'' call.

FILES    [Toc]    [Back]

     /dev/ch[0-9]  device entries

SEE ALSO    [Toc]    [Back]

     cd(4), intro(4), scsi(4), sd(4), st(4)

DISCLAIMER    [Toc]    [Back]

     These  manpages  were derived from the FreeBSD documentation
of the generic
     SCSI drivers.  Since naming and calling conventions may have
diverged or
     suffered  port specific changes, please review the appropriate header
     files and configuration file for your port.

HISTORY    [Toc]    [Back]

     The ch driver appeared in 386BSD 0.1.

OpenBSD     3.6                          March      28,      1997
[ Back ]
 Similar pages
Name OS Title
mcutil Tru64 Media changer manipulation utility
mcicap Tru64 media changer capability database
mc HP-UX media changer manipulation utility
mc Tru64 SCSI medium changer interface
autochanger HP-UX SCSI interfaces for medium changer device and magnetooptical autochanger surface device
nsp FreeBSD Workbit Ninja SCSI-3 based PC-Card SCSI host adapter driver
lmc FreeBSD LAN Media Corp. PCI WAN adapter driver
cmpci OpenBSD C-Media CMI8x38 audio PCI device driver
lmc OpenBSD Lan Media Corporation SSI/DS1/HSSI/DS3 card device driver
dcphy OpenBSD Pseudo-driver for media support on DEC 21143 controllers
Copyright © 2004-2005 DeniX Solutions SRL
newsletter delivery service