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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
Arjan van de Vena3640922008-09-21 15:44:32 -070033config MD_AUTODETECT
34 bool "Autodetect RAID arrays during kernel boot"
Alan Jenkinsce52aeb2008-10-10 16:02:53 +010035 depends on BLK_DEV_MD=y
Arjan van de Vena3640922008-09-21 15:44:32 -070036 default y
37 ---help---
38 If you say Y here, then the kernel will try to autodetect raid
39 arrays as part of its boot process.
40
41 If you don't use raid and say Y, this autodetection can cause
42 a several-second delay in the boot time due to various
43 synchronisation steps that are part of this step.
44
45 If unsure, say Y.
46
Linus Torvalds1da177e2005-04-16 15:20:36 -070047config MD_LINEAR
48 tristate "Linear (append) mode"
49 depends on BLK_DEV_MD
50 ---help---
51 If you say Y here, then your multiple devices driver will be able to
52 use the so-called linear mode, i.e. it will combine the hard disk
53 partitions by simply appending one to the other.
54
55 To compile this as a module, choose M here: the module
56 will be called linear.
57
58 If unsure, say Y.
59
60config MD_RAID0
61 tristate "RAID-0 (striping) mode"
62 depends on BLK_DEV_MD
63 ---help---
64 If you say Y here, then your multiple devices driver will be able to
65 use the so-called raid0 mode, i.e. it will combine the hard disk
66 partitions into one logical device in such a fashion as to fill them
67 up evenly, one chunk here and one chunk there. This will increase
68 the throughput rate if the partitions reside on distinct disks.
69
70 Information about Software RAID on Linux is contained in the
71 Software-RAID mini-HOWTO, available from
72 <http://www.tldp.org/docs.html#howto>. There you will also
73 learn where to get the supporting user space utilities raidtools.
74
75 To compile this as a module, choose M here: the module
76 will be called raid0.
77
78 If unsure, say Y.
79
80config MD_RAID1
81 tristate "RAID-1 (mirroring) mode"
82 depends on BLK_DEV_MD
83 ---help---
84 A RAID-1 set consists of several disk drives which are exact copies
85 of each other. In the event of a mirror failure, the RAID driver
86 will continue to use the operational mirrors in the set, providing
87 an error free MD (multiple device) to the higher levels of the
88 kernel. In a set with N drives, the available space is the capacity
89 of a single drive, and the set protects against a failure of (N - 1)
90 drives.
91
92 Information about Software RAID on Linux is contained in the
93 Software-RAID mini-HOWTO, available from
94 <http://www.tldp.org/docs.html#howto>. There you will also
95 learn where to get the supporting user space utilities raidtools.
96
97 If you want to use such a RAID-1 set, say Y. To compile this code
98 as a module, choose M here: the module will be called raid1.
99
100 If unsure, say Y.
101
102config MD_RAID10
103 tristate "RAID-10 (mirrored striping) mode (EXPERIMENTAL)"
104 depends on BLK_DEV_MD && EXPERIMENTAL
105 ---help---
106 RAID-10 provides a combination of striping (RAID-0) and
Justin Piszcz4d2554d2006-06-26 00:27:50 -0700107 mirroring (RAID-1) with easier configuration and more flexible
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 layout.
109 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
110 be the same size (or at least, only as much as the smallest device
111 will be used).
112 RAID-10 provides a variety of layouts that provide different levels
113 of redundancy and performance.
114
115 RAID-10 requires mdadm-1.7.0 or later, available at:
116
117 ftp://ftp.kernel.org/pub/linux/utils/raid/mdadm/
118
119 If unsure, say Y.
120
NeilBrown16a53ec2006-06-26 00:27:38 -0700121config MD_RAID456
122 tristate "RAID-4/RAID-5/RAID-6 mode"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 depends on BLK_DEV_MD
Dan Williamsf701d582009-03-31 15:09:39 +1100124 select MD_RAID6_PQ
Dan Williams9bc89cd2007-01-02 11:10:44 -0700125 select ASYNC_MEMCPY
126 select ASYNC_XOR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 ---help---
128 A RAID-5 set of N drives with a capacity of C MB per drive provides
129 the capacity of C * (N - 1) MB, and protects against a failure
130 of a single drive. For a given sector (row) number, (N - 1) drives
131 contain data sectors, and one drive contains the parity protection.
132 For a RAID-4 set, the parity blocks are present on a single drive,
133 while a RAID-5 set distributes the parity across the drives in one
134 of the available parity distribution methods.
135
NeilBrown16a53ec2006-06-26 00:27:38 -0700136 A RAID-6 set of N drives with a capacity of C MB per drive
137 provides the capacity of C * (N - 2) MB, and protects
138 against a failure of any two drives. For a given sector
139 (row) number, (N - 2) drives contain data sectors, and two
140 drives contains two independent redundancy syndromes. Like
141 RAID-5, RAID-6 distributes the syndromes across the drives
142 in one of the available parity distribution methods.
143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 Information about Software RAID on Linux is contained in the
145 Software-RAID mini-HOWTO, available from
146 <http://www.tldp.org/docs.html#howto>. There you will also
147 learn where to get the supporting user space utilities raidtools.
148
NeilBrown16a53ec2006-06-26 00:27:38 -0700149 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 compile this code as a module, choose M here: the module
NeilBrown16a53ec2006-06-26 00:27:38 -0700151 will be called raid456.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
153 If unsure, say Y.
154
Dan Williamsf701d582009-03-31 15:09:39 +1100155config MD_RAID6_PQ
156 tristate
157
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158config MD_MULTIPATH
159 tristate "Multipath I/O support"
160 depends on BLK_DEV_MD
161 help
162 Multipath-IO is the ability of certain devices to address the same
163 physical disk over multiple 'IO paths'. The code ensures that such
164 paths can be defined and handled at runtime, and ensures that a
165 transparent failover to the backup path(s) happens if a IO errors
166 arrives on the primary path.
167
168 If unsure, say N.
169
170config MD_FAULTY
171 tristate "Faulty test module for MD"
172 depends on BLK_DEV_MD
173 help
174 The "faulty" module allows for a block device that occasionally returns
175 read or write errors. It is useful for testing.
176
177 In unsure, say N.
178
179config BLK_DEV_DM
180 tristate "Device mapper support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 ---help---
182 Device-mapper is a low level volume manager. It works by allowing
183 people to specify mappings for ranges of logical sectors. Various
184 mapping types are available, in addition people may write their own
185 modules containing custom mappings if they wish.
186
187 Higher level volume managers such as LVM2 use this driver.
188
189 To compile this as a module, choose M here: the module will be
190 called dm-mod.
191
192 If unsure, say N.
193
Bryn Reevescc109202006-10-03 01:15:35 -0700194config DM_DEBUG
195 boolean "Device mapper debugging support"
Alasdair G Kergon0149e572008-02-08 02:10:32 +0000196 depends on BLK_DEV_DM
Bryn Reevescc109202006-10-03 01:15:35 -0700197 ---help---
198 Enable this for messages that may help debug device-mapper problems.
199
200 If unsure, say N.
201
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202config DM_CRYPT
203 tristate "Crypt target support"
Alasdair G Kergon0149e572008-02-08 02:10:32 +0000204 depends on BLK_DEV_DM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 select CRYPTO
Herbert Xu32632632006-12-10 09:50:36 +1100206 select CRYPTO_CBC
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 ---help---
208 This device-mapper target allows you to create a device that
209 transparently encrypts the data on it. You'll need to activate
210 the ciphers you're going to use in the cryptoapi configuration.
211
212 Information on how to use dm-crypt can be found on
213
214 <http://www.saout.de/misc/dm-crypt/>
215
216 To compile this code as a module, choose M here: the module will
217 be called dm-crypt.
218
219 If unsure, say N.
220
221config DM_SNAPSHOT
Alasdair G Kergon0149e572008-02-08 02:10:32 +0000222 tristate "Snapshot target"
223 depends on BLK_DEV_DM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 ---help---
Justin Piszcz4d2554d2006-06-26 00:27:50 -0700225 Allow volume managers to take writable snapshots of a device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
227config DM_MIRROR
Alasdair G Kergon0149e572008-02-08 02:10:32 +0000228 tristate "Mirror target"
229 depends on BLK_DEV_DM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 ---help---
231 Allow volume managers to mirror logical volumes, also
232 needed for live data migration tools such as 'pvmove'.
233
234config DM_ZERO
Alasdair G Kergon0149e572008-02-08 02:10:32 +0000235 tristate "Zero target"
236 depends on BLK_DEV_DM
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 ---help---
238 A target that discards writes, and returns all zeroes for
239 reads. Useful in some recovery situations.
240
241config DM_MULTIPATH
Alasdair G Kergon0149e572008-02-08 02:10:32 +0000242 tristate "Multipath target"
243 depends on BLK_DEV_DM
Chandra Seetharamanfe9233f2008-05-23 18:16:40 -0700244 # nasty syntax but means make DM_MULTIPATH independent
245 # of SCSI_DH if the latter isn't defined but if
246 # it is, DM_MULTIPATH must depend on it. We get a build
247 # error if SCSI_DH=m and DM_MULTIPATH=y
248 depends on SCSI_DH || !SCSI_DH
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 ---help---
250 Allow volume managers to support multipath hardware.
251
Heinz Mauelshagen26b9f222007-05-09 02:33:06 -0700252config DM_DELAY
253 tristate "I/O delaying target (EXPERIMENTAL)"
254 depends on BLK_DEV_DM && EXPERIMENTAL
255 ---help---
256 A target that delays reads and/or writes and can send
257 them to different devices. Useful for testing.
258
259 If unsure, say N.
260
Mike Anderson51e5b2b2007-10-19 22:48:00 +0100261config DM_UEVENT
262 bool "DM uevents (EXPERIMENTAL)"
263 depends on BLK_DEV_DM && EXPERIMENTAL
264 ---help---
265 Generate udev events for DM events.
266
Jan Engelhardtafd44032007-07-17 04:06:11 -0700267endif # MD