Commit | Line | Data |
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1da177e4 LT |
1 | # |
2 | # Block device driver configuration | |
3 | # | |
4 | ||
afd44034 | 5 | menuconfig MD |
1da177e4 | 6 | bool "Multiple devices driver support (RAID and LVM)" |
afd44034 | 7 | depends on BLOCK |
1da177e4 LT |
8 | help |
9 | Support multiple physical spindles through a single logical device. | |
10 | Required for RAID and logical volume management. | |
11 | ||
afd44034 JE |
12 | if MD |
13 | ||
1da177e4 LT |
14 | config BLK_DEV_MD |
15 | tristate "RAID support" | |
1da177e4 LT |
16 | ---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 | ||
a364092a AV |
33 | config MD_AUTODETECT |
34 | bool "Autodetect RAID arrays during kernel boot" | |
ce52aebd | 35 | depends on BLK_DEV_MD=y |
a364092a AV |
36 | 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 | ||
1da177e4 LT |
47 | config 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 | ||
60 | config 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 | ||
80 | config 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 | ||
102 | config 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 | |
4d2554d0 | 107 | mirroring (RAID-1) with easier configuration and more flexible |
1da177e4 LT |
108 | 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 | ||
16a53ecc N |
121 | config MD_RAID456 |
122 | tristate "RAID-4/RAID-5/RAID-6 mode" | |
1da177e4 | 123 | depends on BLK_DEV_MD |
f701d589 | 124 | select MD_RAID6_PQ |
9bc89cd8 DW |
125 | select ASYNC_MEMCPY |
126 | select ASYNC_XOR | |
1da177e4 LT |
127 | ---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 | ||
16a53ecc N |
136 | 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 | ||
1da177e4 LT |
144 | 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 | ||
16a53ecc | 149 | If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To |
1da177e4 | 150 | compile this code as a module, choose M here: the module |
16a53ecc | 151 | will be called raid456. |
1da177e4 LT |
152 | |
153 | If unsure, say Y. | |
154 | ||
f701d589 DW |
155 | config MD_RAID6_PQ |
156 | tristate | |
157 | ||
1da177e4 LT |
158 | config 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 | ||
170 | config 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 | ||
179 | config BLK_DEV_DM | |
180 | tristate "Device mapper support" | |
1da177e4 LT |
181 | ---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 | ||
cc109201 BR |
194 | config DM_DEBUG |
195 | boolean "Device mapper debugging support" | |
0149e57f | 196 | depends on BLK_DEV_DM |
cc109201 BR |
197 | ---help--- |
198 | Enable this for messages that may help debug device-mapper problems. | |
199 | ||
200 | If unsure, say N. | |
201 | ||
1da177e4 LT |
202 | config DM_CRYPT |
203 | tristate "Crypt target support" | |
0149e57f | 204 | depends on BLK_DEV_DM |
1da177e4 | 205 | select CRYPTO |
3263263f | 206 | select CRYPTO_CBC |
1da177e4 LT |
207 | ---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 | ||
221 | config DM_SNAPSHOT | |
0149e57f AK |
222 | tristate "Snapshot target" |
223 | depends on BLK_DEV_DM | |
1da177e4 | 224 | ---help--- |
4d2554d0 | 225 | Allow volume managers to take writable snapshots of a device. |
1da177e4 LT |
226 | |
227 | config DM_MIRROR | |
0149e57f AK |
228 | tristate "Mirror target" |
229 | depends on BLK_DEV_DM | |
1da177e4 LT |
230 | ---help--- |
231 | Allow volume managers to mirror logical volumes, also | |
232 | needed for live data migration tools such as 'pvmove'. | |
233 | ||
234 | config DM_ZERO | |
0149e57f AK |
235 | tristate "Zero target" |
236 | depends on BLK_DEV_DM | |
1da177e4 LT |
237 | ---help--- |
238 | A target that discards writes, and returns all zeroes for | |
239 | reads. Useful in some recovery situations. | |
240 | ||
241 | config DM_MULTIPATH | |
0149e57f AK |
242 | tristate "Multipath target" |
243 | depends on BLK_DEV_DM | |
fe9233fb CS |
244 | # 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 | |
1da177e4 LT |
249 | ---help--- |
250 | Allow volume managers to support multipath hardware. | |
251 | ||
26b9f228 HM |
252 | config 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 | ||
51e5b2bd MA |
261 | config DM_UEVENT |
262 | bool "DM uevents (EXPERIMENTAL)" | |
263 | depends on BLK_DEV_DM && EXPERIMENTAL | |
264 | ---help--- | |
265 | Generate udev events for DM events. | |
266 | ||
afd44034 | 267 | endif # MD |