NATARAID(4)

NAME
nataraid, ar - ATA software RAID support

SYNOPSIS
To compile this driver into the kernel, place the following lines in your kernel configuration file:

device nata
device nataraid

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

    nataraid_load="YES"

DESCRIPTION
The nataraid driver provides support for so-called software RAID (sometimes referred to as fake RAID or pseudo RAID).

When a controller that supports software RAID is instructed to create a RAID array, its BIOS writes data structures in a specific metadata format to the disks. These data structures are picked up by the nataraid driver, so that DragonFly can work with the array. The nataraid driver has to understand the specific metadata format of a controller BIOS in order to support its RAID capabilities.

Read-only support for a metadata format means that DragonFly can use the given RAID array for normal read/write operations. Creation and rebuild of such arrays has to be done from the controller BIOS.

Read and write support for a metadata format means that DragonFly can use the given RAID array for normal read/write operations. Additionally, the natacontrol(8) utility can be used to create, rebuild, update and fail such RAID arrays.

The nataraid driver can read the following metadata formats:

•   Adaptec HostRAID
•   Highpoint V2 RocketRAID
•   Highpoint V3 RocketRAID
•   Intel MatrixRAID
•   Integrated Technology Express (ITE)
•   JMicron
•   LSI Logic V2 MegaRAID
•   LSI Logic V3 MegaRAID
•   NVIDIA MediaShield
•   Promise FastTrak
•   Silicon Image Medley
•   Silicon Integrated Systems (SiS)
•   VIA Tech V-RAID
•   FreeBSD PseudoRAID

The nataraid driver can write the following metadata formats:

•   Highpoint V2 RocketRAID
•   Intel MatrixRAID
•   JMicron
•   Promise FastTrak
•   Silicon Integrated Systems (SiS)
•   VIA Tech V-RAID
•   FreeBSD PseudoRAID

It is also possible to use software RAID on controllers that do not have special software RAID capabilities. See natacontrol(8) for details.

FILES
/dev/ar*
    ATA RAID device nodes

SEE ALSO
nata(4), natacontrol(8)

CAVEATS
RAID5 is not supported at this time. Code exists, but it neither uses nor maintains parity information.

AUTHORS
-nosplit The nataraid driver was written by Søren Schmidt <sos@FreeBSD.org>. This manual page was written by Christian Brueffer <brueffer@FreeBSD.org>.