BIO(4)                  NetBSD Kernel Interfaces Manual                 BIO(4)

NAME
     bio -- Block IO ioctl tunnel pseudo-device

SYNOPSIS
     pseudo-device bio

DESCRIPTION
     The bio driver provides userland applications ioctl(2) access to devices
     otherwise not found as /dev nodes.  The /dev/bio device node operates by
     delegating ioctl calls to a requested device driver.  Only drivers which
     have registered with the bio device can be accessed via this interface.

     The following device drivers register with bio for volume management:

           arcmsr(4)  Areca Technology Corporation SATA RAID controller
           cac(4)     Compaq RAID array controller
           ciss(4)    Compaq Smart ARRAY 5/6 SAS/SATA/SCSI RAID controller
           mfi(4)     LSI Logic & Dell MegaRAID SAS RAID controller

     The following ioctl calls apply to the bio device:

     BIOCLOCATE        Locate a named device and give back a cookie to the
                       application for subsequent ioctl calls.  The cookie is
                       used to tunnel further ioctls to the right device.

     BIOCINQ           Retrieve number of volumes and physical disks for a
                       specific device.

     BIOCDISK          Retrieve detailed information for the specified physi-
                       cal disk.  Information returned can include status,
                       size, channel, target, lun, vendor name, serial number,
                       and processor device (ses or safte).

     BIOCDISK_NOVOL    Is just the same as BIOCDISK but doesn't require the
                       disks to be in volume sets, so this applies to any
                       physical disk connected to the controller.

                       Note: this ioctl might not be supported on all hard-
                       ware.

     BIOCVOL           Retrieve detailed information for the specified volume.
                       Information returned can include status, size, RAID
                       level, number of disks, device name association (sd?)
                       and vendor name.

     BIOCALARM         Control the alarm beeper on the device.  Supported
                       states are: disable alarm, enable alarm, silence alarm,
                       status and test alarm.

                       Note:  These options might not be supported on all
                       hardware.

     BIOCBLINK         Blink an LED of the specified physical disk.  Supported
                       blink states are: blink LED, unblink LED and blink
                       alarm LED.

                       Note:  This option is only supported if the disk is
                       governed by ses(4) or safte(4) and the hardware sup-
                       ports hardware blinking.

     BIOCSETSTATE      Alter the state of specified physical disk.  Supported
                       states are: create/remove hot-spare, create/remove pass
                       through disk, start/stop consistency check in a volume,
                       online disk and offline disk.

                       Note:  These options might not be supported on all
                       hardware.

     BIOCVOLOPS        For operations in volume sets. It's able to create and
                       remove a volume set in a supported RAID controller.

                       Note: this ioctl might not be supported on all hard-
                       ware.

FILES
     /dev/bio  ioctl tunnel device

SEE ALSO
     ioctl(2), bioctl(8)

HISTORY
     The bio driver first appeared in OpenBSD 3.2 and NetBSD 4.0.

AUTHORS
     The bio driver was written by Niklas Hallqvist <niklas@openbsd.org>.  The
     API was written by Marco Peereboom <marco@openbsd.org> and was extended
     even more for NetBSD by Juan Romero Pardines <xtraeme@netbsd.org>.

NetBSD 5.0_STABLE                May 25, 2008                NetBSD 5.0_STABLE
