/dev/bio
ioctl tunnel device
Block i/o ioctl tunnel pseudo-device
pseudo-device bio [count]
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.
If count is given in the specification, and is greater than 0, a maximum of one bio device is created.
The following device drivers register with bio for volume management:
American Megatrends Inc. MegaRAID PATA/SATA/SCSI RAID controller
Areca Technology Corporation SAS/SATA RAID controller
Compaq Smart Array 2/3/4 SCSI RAID controller
Compaq Smart Array SAS/SATA/SCSI RAID controller
ICP-Vortex and Intel GDT SATA/SCSI RAID controller
IBM SATA/SCSI ServeRAID controller
LSI Logic & Dell MegaRAID SAS RAID controller
LSI Logic MegaRAID SAS Fusion RAID controller
LSI Logic Fusion-MPT Message Passing Interface
LSI Logic Fusion-MPT Message Passing Interface II
NVMe storage controllers
Software RAID
The following device drivers register with bio to provide enclosure management:
SCSI Enclosure Services
The following ioctl calls apply to the bio device:
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.
Retrieve number of volumes and physical disks for a specific device.
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).
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.
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.
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.
Alter the state of specified physical disk. Supported states are: create hot-spare, online disk and offline disk.
The following ioctl calls apply to the bio device only when talking to a softraid(4) device:
Create a new volume or assemble an existing volume. The volume will be attached as a system disk, if this capability is supported by the volume discipline.
Remove system disk (if present) and disassemble the softraid(4) volume.
Dispatch a discipline specific ioctl.
Install a boot loader.
/dev/bio
ioctl tunnel device
50 releases since OpenBSD 3.2; the text changed 19 times.