xref: /dragonfly/share/man/man4/nataraid.4 (revision 82730a9c)
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25.\" $FreeBSD: src/share/man/man4/ataraid.4,v 1.10 2006/09/18 15:24:18 ru Exp $
26.\"
27.Dd June 24, 2007
28.Dt NATARAID 4
29.Os
30.Sh NAME
31.Nm nataraid ,
32.Nm ar
33.Nd "ATA software RAID support"
34.Sh SYNOPSIS
35.Cd "device nata"
36.Cd "device nataraid"
37.Sh DESCRIPTION
38The
39.Nm
40driver provides support for so-called software RAID
41(sometimes referred to as fake RAID or pseudo RAID).
42.Pp
43When a controller that supports software RAID is instructed to
44create a RAID array, its BIOS writes data structures in a specific
45metadata format to the disks.
46These data structures are picked up by the
47.Nm
48driver, so that
49.Dx
50can work with the array.
51The
52.Nm
53driver has to understand the specific metadata format of a
54controller BIOS in order to support its RAID capabilities.
55.Pp
56Read-only support for a metadata format means that
57.Dx
58can use the given RAID array for normal read/write operations.
59Creation and rebuild of such arrays has to be done from the
60controller BIOS.
61.Pp
62Read and write support for a metadata format means that
63.Dx
64can use the given RAID array for normal read/write operations.
65Additionally, the
66.Xr natacontrol 8
67utility can be used to create, rebuild, update and fail such
68RAID arrays.
69.Pp
70The
71.Nm
72driver can read the following metadata formats:
73.Pp
74.Bl -bullet -compact
75.It
76Adaptec HostRAID
77.It
78Highpoint V2 RocketRAID
79.It
80Highpoint V3 RocketRAID
81.It
82Intel MatrixRAID
83.It
84Integrated Technology Express (ITE)
85.It
86JMicron
87.It
88LSI Logic V2 MegaRAID
89.It
90LSI Logic V3 MegaRAID
91.It
92NVIDIA MediaShield
93.It
94Promise FastTrak
95.It
96Silicon Image Medley
97.It
98Silicon Integrated Systems (SiS)
99.It
100VIA Tech V-RAID
101.It
102FreeBSD PseudoRAID
103.El
104.Pp
105The
106.Nm
107driver can write the following metadata formats:
108.Pp
109.Bl -bullet -compact
110.It
111Highpoint V2 RocketRAID
112.It
113Intel MatrixRAID
114.It
115JMicron
116.It
117Promise FastTrak
118.It
119Silicon Integrated Systems (SiS)
120.It
121VIA Tech V-RAID
122.It
123FreeBSD PseudoRAID
124.El
125.Pp
126It is also possible to use software RAID on controllers
127that do not have special software RAID capabilities.
128See
129.Xr natacontrol 8
130for details.
131.Sh FILES
132.Bl -tag -width ".Pa /dev/ar*" -compact
133.It Pa /dev/ar*
134ATA RAID device nodes
135.El
136.Sh SEE ALSO
137.Xr nata 4 ,
138.Xr natacontrol 8
139.Sh CAVEATS
140RAID5 is not supported at this time.
141Code exists, but it neither uses nor maintains parity information.
142.Sh AUTHORS
143.An -nosplit
144The
145.Nm
146driver was written by
147.An S\(/oren Schmidt Aq Mt sos@FreeBSD.org .
148This manual page was written by
149.An Christian Brueffer Aq Mt brueffer@FreeBSD.org .
150