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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#
2# Block device driver configuration
3#
4
Jan Engelhardtafd44032007-07-17 04:06:11 -07005menuconfig MD
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 bool "Multiple devices driver support (RAID and LVM)"
Jan Engelhardtafd44032007-07-17 04:06:11 -07007 depends on BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 help
9 Support multiple physical spindles through a single logical device.
10 Required for RAID and logical volume management.
11
Jan Engelhardtafd44032007-07-17 04:06:11 -070012if MD
13
Linus Torvalds1da177e2005-04-16 15:20:36 -070014config BLK_DEV_MD
15 tristate "RAID support"
Linus Torvalds1da177e2005-04-16 15:20:36 -070016 ---help---
17 This driver lets you combine several hard disk partitions into one
18 logical block device. This can be used to simply append one
19 partition to another one or to combine several redundant hard disks
20 into a RAID1/4/5 device so as to provide protection against hard
21 disk failures. This is called "Software RAID" since the combining of
22 the partitions is done by the kernel. "Hardware RAID" means that the
23 combining is done by a dedicated controller; if you have such a
24 controller, you do not need to say Y here.
25
26 More information about Software RAID on Linux is contained in the
27 Software RAID mini-HOWTO, available from
28 <http://www.tldp.org/docs.html#howto>. There you will also learn
29 where to get the supporting user space utilities raidtools.
30
31 If unsure, say N.
32
33config MD_LINEAR
34 tristate "Linear (append) mode"
35 depends on BLK_DEV_MD
36 ---help---
37 If you say Y here, then your multiple devices driver will be able to
38 use the so-called linear mode, i.e. it will combine the hard disk
39 partitions by simply appending one to the other.
40
41 To compile this as a module, choose M here: the module
42 will be called linear.
43
44 If unsure, say Y.
45
46config MD_RAID0
47 tristate "RAID-0 (striping) mode"
48 depends on BLK_DEV_MD
49 ---help---
50 If you say Y here, then your multiple devices driver will be able to
51 use the so-called raid0 mode, i.e. it will combine the hard disk
52 partitions into one logical device in such a fashion as to fill them
53 up evenly, one chunk here and one chunk there. This will increase
54 the throughput rate if the partitions reside on distinct disks.
55
56 Information about Software RAID on Linux is contained in the
57 Software-RAID mini-HOWTO, available from
58 <http://www.tldp.org/docs.html#howto>. There you will also
59 learn where to get the supporting user space utilities raidtools.
60
61 To compile this as a module, choose M here: the module
62 will be called raid0.
63
64 If unsure, say Y.
65
66config MD_RAID1
67 tristate "RAID-1 (mirroring) mode"
68 depends on BLK_DEV_MD
69 ---help---
70 A RAID-1 set consists of several disk drives which are exact copies
71 of each other. In the event of a mirror failure, the RAID driver
72 will continue to use the operational mirrors in the set, providing
73 an error free MD (multiple device) to the higher levels of the
74 kernel. In a set with N drives, the available space is the capacity
75 of a single drive, and the set protects against a failure of (N - 1)
76 drives.
77
78 Information about Software RAID on Linux is contained in the
79 Software-RAID mini-HOWTO, available from
80 <http://www.tldp.org/docs.html#howto>. There you will also
81 learn where to get the supporting user space utilities raidtools.
82
83 If you want to use such a RAID-1 set, say Y. To compile this code
84 as a module, choose M here: the module will be called raid1.
85
86 If unsure, say Y.
87
88config MD_RAID10
89 tristate "RAID-10 (mirrored striping) mode (EXPERIMENTAL)"
90 depends on BLK_DEV_MD && EXPERIMENTAL
91 ---help---
92 RAID-10 provides a combination of striping (RAID-0) and
Justin Piszcz4d2554d2006-06-26 00:27:50 -070093 mirroring (RAID-1) with easier configuration and more flexible
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 layout.
95 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
96 be the same size (or at least, only as much as the smallest device
97 will be used).
98 RAID-10 provides a variety of layouts that provide different levels
99 of redundancy and performance.
100
101 RAID-10 requires mdadm-1.7.0 or later, available at:
102
103 ftp://ftp.kernel.org/pub/linux/utils/raid/mdadm/
104
105 If unsure, say Y.
106
NeilBrown16a53ec2006-06-26 00:27:38 -0700107config MD_RAID456
108 tristate "RAID-4/RAID-5/RAID-6 mode"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 depends on BLK_DEV_MD
Dan Williams9bc89cd2007-01-02 11:10:44 -0700110 select ASYNC_MEMCPY
111 select ASYNC_XOR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 ---help---
113 A RAID-5 set of N drives with a capacity of C MB per drive provides
114 the capacity of C * (N - 1) MB, and protects against a failure
115 of a single drive. For a given sector (row) number, (N - 1) drives
116 contain data sectors, and one drive contains the parity protection.
117 For a RAID-4 set, the parity blocks are present on a single drive,
118 while a RAID-5 set distributes the parity across the drives in one
119 of the available parity distribution methods.
120
NeilBrown16a53ec2006-06-26 00:27:38 -0700121 A RAID-6 set of N drives with a capacity of C MB per drive
122 provides the capacity of C * (N - 2) MB, and protects
123 against a failure of any two drives. For a given sector
124 (row) number, (N - 2) drives contain data sectors, and two
125 drives contains two independent redundancy syndromes. Like
126 RAID-5, RAID-6 distributes the syndromes across the drives
127 in one of the available parity distribution methods.
128
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 Information about Software RAID on Linux is contained in the
130 Software-RAID mini-HOWTO, available from
131 <http://www.tldp.org/docs.html#howto>. There you will also
132 learn where to get the supporting user space utilities raidtools.
133
NeilBrown16a53ec2006-06-26 00:27:38 -0700134 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 compile this code as a module, choose M here: the module
NeilBrown16a53ec2006-06-26 00:27:38 -0700136 will be called raid456.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137
138 If unsure, say Y.
139
NeilBrown29269552006-03-27 01:18:10 -0800140config MD_RAID5_RESHAPE
NeilBrown14f50b42006-10-03 01:16:00 -0700141 bool "Support adding drives to a raid-5 array"
142 depends on MD_RAID456
143 default y
NeilBrown29269552006-03-27 01:18:10 -0800144 ---help---
145 A RAID-5 set can be expanded by adding extra drives. This
146 requires "restriping" the array which means (almost) every
147 block must be written to a different place.
148
149 This option allows such restriping to be done while the array
NeilBrown14f50b42006-10-03 01:16:00 -0700150 is online.
NeilBrown29269552006-03-27 01:18:10 -0800151
Justin Piszcz4d2554d2006-06-26 00:27:50 -0700152 You will need mdadm version 2.4.1 or later to use this
NeilBrown6f91fe82006-04-10 22:52:48 -0700153 feature safely. During the early stage of reshape there is
154 a critical section where live data is being over-written. A
155 crash during this time needs extra care for recovery. The
156 newer mdadm takes a copy of the data in the critical section
157 and will restore it, if necessary, after a crash.
NeilBrown29269552006-03-27 01:18:10 -0800158
159 The mdadm usage is e.g.
160 mdadm --grow /dev/md1 --raid-disks=6
161 to grow '/dev/md1' to having 6 disks.
162
163 Note: The array can only be expanded, not contracted.
164 There should be enough spares already present to make the new
165 array workable.
166
NeilBrown14f50b42006-10-03 01:16:00 -0700167 If unsure, say Y.
168
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169config MD_MULTIPATH
170 tristate "Multipath I/O support"
171 depends on BLK_DEV_MD
172 help
173 Multipath-IO is the ability of certain devices to address the same
174 physical disk over multiple 'IO paths'. The code ensures that such
175 paths can be defined and handled at runtime, and ensures that a
176 transparent failover to the backup path(s) happens if a IO errors
177 arrives on the primary path.
178
179 If unsure, say N.
180
181config MD_FAULTY
182 tristate "Faulty test module for MD"
183 depends on BLK_DEV_MD
184 help
185 The "faulty" module allows for a block device that occasionally returns
186 read or write errors. It is useful for testing.
187
188 In unsure, say N.
189
190config BLK_DEV_DM
191 tristate "Device mapper support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 ---help---
193 Device-mapper is a low level volume manager. It works by allowing
194 people to specify mappings for ranges of logical sectors. Various
195 mapping types are available, in addition people may write their own
196 modules containing custom mappings if they wish.
197
198 Higher level volume managers such as LVM2 use this driver.
199
200 To compile this as a module, choose M here: the module will be
201 called dm-mod.
202
203 If unsure, say N.
204
Bryn Reevescc109202006-10-03 01:15:35 -0700205config DM_DEBUG
206 boolean "Device mapper debugging support"
207 depends on BLK_DEV_DM && EXPERIMENTAL
208 ---help---
209 Enable this for messages that may help debug device-mapper problems.
210
211 If unsure, say N.
212
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213config DM_CRYPT
214 tristate "Crypt target support"
215 depends on BLK_DEV_DM && EXPERIMENTAL
216 select CRYPTO
Herbert Xu32632632006-12-10 09:50:36 +1100217 select CRYPTO_CBC
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 ---help---
219 This device-mapper target allows you to create a device that
220 transparently encrypts the data on it. You'll need to activate
221 the ciphers you're going to use in the cryptoapi configuration.
222
223 Information on how to use dm-crypt can be found on
224
225 <http://www.saout.de/misc/dm-crypt/>
226
227 To compile this code as a module, choose M here: the module will
228 be called dm-crypt.
229
230 If unsure, say N.
231
232config DM_SNAPSHOT
233 tristate "Snapshot target (EXPERIMENTAL)"
234 depends on BLK_DEV_DM && EXPERIMENTAL
235 ---help---
Justin Piszcz4d2554d2006-06-26 00:27:50 -0700236 Allow volume managers to take writable snapshots of a device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
238config DM_MIRROR
239 tristate "Mirror target (EXPERIMENTAL)"
240 depends on BLK_DEV_DM && EXPERIMENTAL
241 ---help---
242 Allow volume managers to mirror logical volumes, also
243 needed for live data migration tools such as 'pvmove'.
244
245config DM_ZERO
246 tristate "Zero target (EXPERIMENTAL)"
247 depends on BLK_DEV_DM && EXPERIMENTAL
248 ---help---
249 A target that discards writes, and returns all zeroes for
250 reads. Useful in some recovery situations.
251
252config DM_MULTIPATH
253 tristate "Multipath target (EXPERIMENTAL)"
254 depends on BLK_DEV_DM && EXPERIMENTAL
255 ---help---
256 Allow volume managers to support multipath hardware.
257
258config DM_MULTIPATH_EMC
259 tristate "EMC CX/AX multipath support (EXPERIMENTAL)"
260 depends on DM_MULTIPATH && BLK_DEV_DM && EXPERIMENTAL
261 ---help---
262 Multipath support for EMC CX/AX series hardware.
263
Chandra Seetharamandd172d72007-07-12 17:30:05 +0100264config DM_MULTIPATH_RDAC
265 tristate "LSI/Engenio RDAC multipath support (EXPERIMENTAL)"
Randy Dunlap6e106b02007-08-24 15:35:15 -0700266 depends on DM_MULTIPATH && BLK_DEV_DM && SCSI && EXPERIMENTAL
Chandra Seetharamandd172d72007-07-12 17:30:05 +0100267 ---help---
268 Multipath support for LSI/Engenio RDAC.
269
Dave Wysochanski16ebbf32007-10-19 22:47:54 +0100270config DM_MULTIPATH_HP
271 tristate "HP MSA multipath support (EXPERIMENTAL)"
272 depends on DM_MULTIPATH && BLK_DEV_DM && EXPERIMENTAL
273 ---help---
274 Multipath support for HP MSA (Active/Passive) series hardware.
275
Heinz Mauelshagen26b9f222007-05-09 02:33:06 -0700276config DM_DELAY
277 tristate "I/O delaying target (EXPERIMENTAL)"
278 depends on BLK_DEV_DM && EXPERIMENTAL
279 ---help---
280 A target that delays reads and/or writes and can send
281 them to different devices. Useful for testing.
282
283 If unsure, say N.
284
Mike Anderson51e5b2b2007-10-19 22:48:00 +0100285config DM_UEVENT
286 bool "DM uevents (EXPERIMENTAL)"
287 depends on BLK_DEV_DM && EXPERIMENTAL
288 ---help---
289 Generate udev events for DM events.
290
Jan Engelhardtafd44032007-07-17 04:06:11 -0700291endif # MD