BIO(4)							   BSD 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 oper-
     ates 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 physical disk.  Information returned can include status, size, channel,
		       target, lun, vendor name, serial number, and processor device (ses).

     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 con-
		       nected to the controller.

		       Note: this ioctl might not be supported on all hardware.

     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) and the hardware supports 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 hardware.

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>.

BSD
								   May 25, 2008 							       BSD