---
name: "ataraid"
section: "4freebsd"
platform: "linux"
package: "freebsd-manpages"
version: "8.2-1"
release: "Debian 7 (Wheezy)"
platforms: ["linux"]
url: "https://new.carta.tech/ataraid/4freebsd"
---

# ataraid(4freebsd)

ATA software RAID support

## NAME

**ataraid** – ATA software RAID support

## SYNOPSIS

**device ata** **device ataraid**

## DESCRIPTION

The **ataraid** 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 **ataraid** driver, so that FreeBSD can work with the array. The **ataraid** 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 FreeBSD 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 FreeBSD can use the given RAID array for normal read/write operations. Additionally, the atacontrol(8) utility can be used to create, rebuild, update and fail such RAID arrays.

The **ataraid** 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 **ataraid** 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 atacontrol(8) for details.

## FILES

- */dev/ar\**

  ATA RAID device nodes

## SEE ALSO

[ata(4)](/ata/4.md), atacontrol(8)

## CAVEATS

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

## AUTHORS

The **ataraid** driver was written by Søren Schmidt ⟨sos@FreeBSD.org⟩. This manual page was written by Christian Brueffer ⟨brueffer@FreeBSD.org⟩.