xref: /dragonfly/share/man/man4/nataraid.4 (revision d4ef6694) 
1.\" Copyright (c) 2005 Christian Brueffer
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\"    notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\"
13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23.\" SUCH DAMAGE.
24.\"
25.\" $FreeBSD: src/share/man/man4/ataraid.4,v 1.10 2006/09/18 15:24:18 ru Exp $
26.\"
27.Dd February 22, 2014
28.Dt NATARAID 4
29.Os
30.Sh NAME
31.Nm nataraid ,
32.Nm ar
33.Nd "ATA software RAID support"
34.Sh SYNOPSIS
35To compile this driver into the kernel,
36place the following lines in your
37kernel configuration file:
38.Bd -ragged -offset indent
39.Cd "device nata"
40.Cd "device nataraid"
41.Ed
42.Pp
43Alternatively, to load the driver as a
44module at boot time, place the following line in
45.Xr loader.conf 5 :
46.Bd -literal -offset indent
47nataraid_load="YES"
48.Ed
49.Sh DESCRIPTION
50The
51.Nm
52driver provides support for so-called software RAID
53(sometimes referred to as fake RAID or pseudo RAID).
54.Pp
55When a controller that supports software RAID is instructed to
56create a RAID array, its BIOS writes data structures in a specific
57metadata format to the disks.
58These data structures are picked up by the
59.Nm
60driver, so that
61.Dx
62can work with the array.
63The
64.Nm
65driver has to understand the specific metadata format of a
66controller BIOS in order to support its RAID capabilities.
67.Pp
68Read-only support for a metadata format means that
69.Dx
70can use the given RAID array for normal read/write operations.
71Creation and rebuild of such arrays has to be done from the
72controller BIOS.
73.Pp
74Read and write support for a metadata format means that
75.Dx
76can use the given RAID array for normal read/write operations.
77Additionally, the
78.Xr natacontrol 8
79utility can be used to create, rebuild, update and fail such
80RAID arrays.
81.Pp
82The
83.Nm
84driver can read the following metadata formats:
85.Pp
86.Bl -bullet -compact
87.It
88Adaptec HostRAID
89.It
90Highpoint V2 RocketRAID
91.It
92Highpoint V3 RocketRAID
93.It
94Intel MatrixRAID
95.It
96Integrated Technology Express (ITE)
97.It
98JMicron
99.It
100LSI Logic V2 MegaRAID
101.It
102LSI Logic V3 MegaRAID
103.It
104NVIDIA MediaShield
105.It
106Promise FastTrak
107.It
108Silicon Image Medley
109.It
110Silicon Integrated Systems (SiS)
111.It
112VIA Tech V-RAID
113.It
114FreeBSD PseudoRAID
115.El
116.Pp
117The
118.Nm
119driver can write the following metadata formats:
120.Pp
121.Bl -bullet -compact
122.It
123Highpoint V2 RocketRAID
124.It
125Intel MatrixRAID
126.It
127JMicron
128.It
129Promise FastTrak
130.It
131Silicon Integrated Systems (SiS)
132.It
133VIA Tech V-RAID
134.It
135FreeBSD PseudoRAID
136.El
137.Pp
138It is also possible to use software RAID on controllers
139that do not have special software RAID capabilities.
140See
141.Xr natacontrol 8
142for details.
143.Sh FILES
144.Bl -tag -width ".Pa /dev/ar*" -compact
145.It Pa /dev/ar*
146ATA RAID device nodes
147.El
148.Sh SEE ALSO
149.Xr nata 4 ,
150.Xr natacontrol 8
151.Sh CAVEATS
152RAID5 is not supported at this time.
153Code exists, but it neither uses nor maintains parity information.
154.Sh AUTHORS
155.An -nosplit
156The
157.Nm
158driver was written by
159.An S\(/oren Schmidt Aq Mt sos@FreeBSD.org .
160This manual page was written by
161.An Christian Brueffer Aq Mt brueffer@FreeBSD.org .
162