ataraid(4) [netbsd man page]

ATARAID(4)						   BSD Kernel Interfaces Manual 						ATARAID(4)

NAME

     ataraid -- software BIOS RAID

SYNOPSIS

     pseudo-device ataraid
     ld* at ataraid? vendtype ? unit ?

DESCRIPTION

     The ataraid driver provides support for BIOS-based software RAID controllers.  These are devices which have some simple support for several
     basic RAID levels (often RAID 0 and RAID 1), but which require software support to actually perform the RAID function.  The BIOS support is
     largely just to create and recognize the array so that it may be a boot device.

     The driver currently supports RAID formats from:
	   o   Adaptec HostRAID (found in Intel 6300ESB)
	   o   Intel MatrixRAID
	   o   JMicron RAID
	   o   nVidia MediaShield
	   o   Promise FastTrak
	   o   Via V-RAID (found in many VIA-based motherboards)

     Status of the logical disk as well as the disks associated with it, can be viewed through the bioctl(8) utility.

SEE ALSO

     ld(4), bioctl(8)

HISTORY

     The ataraid driver first appeared in NetBSD 2.0.

AUTHORS

     The ataraid driver was originally adapted from FreeBSD by Jason Thorpe <thorpej@NetBSD.org>.

BUGS

     Not all features of the software RAID are currently recognized or supported.  For example, the Adaptec support doesn't recognize when a RAID
     1 should be in a ``building'' state, and it does not do the right thing.

     At least part of the reason for this is that the publically-available information on these formats is quite limited.

BSD
								September 16, 2008							       BSD

ATARAID(4)                                                 BSD Kernel Interfaces Manual                                                 ATARAID(4)

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:

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

     The ataraid driver can write the following metadata formats:

     o   Highpoint V2 RocketRAID
     o   Intel MatrixRAID
     o   JMicron
     o   Promise FastTrak
     o   Silicon Integrated Systems (SiS)
     o   VIA Tech V-RAID
     o   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), 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 Soren Schmidt <sos@FreeBSD.org>.  This manual page was written by Christian Brueffer
     <brueffer@FreeBSD.org>.

BSD                                                              February 17, 2006                                                             BSD