Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | # |
| 2 | # Block device driver configuration |
| 3 | # |
| 4 | |
Jan Engelhardt | afd4403 | 2007-07-17 04:06:11 -0700 | [diff] [blame] | 5 | menuconfig MD |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | bool "Multiple devices driver support (RAID and LVM)" |
Jan Engelhardt | afd4403 | 2007-07-17 04:06:11 -0700 | [diff] [blame] | 7 | depends on BLOCK |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | help |
| 9 | Support multiple physical spindles through a single logical device. |
| 10 | Required for RAID and logical volume management. |
| 11 | |
Jan Engelhardt | afd4403 | 2007-07-17 04:06:11 -0700 | [diff] [blame] | 12 | if MD |
| 13 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | config BLK_DEV_MD |
| 15 | tristate "RAID support" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Arjan van de Ven | a364092 | 2008-09-21 15:44:32 -0700 | [diff] [blame] | 33 | config MD_AUTODETECT |
| 34 | bool "Autodetect RAID arrays during kernel boot" |
Alan Jenkins | ce52aeb | 2008-10-10 16:02:53 +0100 | [diff] [blame] | 35 | depends on BLK_DEV_MD=y |
Arjan van de Ven | a364092 | 2008-09-21 15:44:32 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
Justin Piszcz | 4d2554d | 2006-06-26 00:27:50 -0700 | [diff] [blame] | 107 | mirroring (RAID-1) with easier configuration and more flexible |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
NeilBrown | 16a53ec | 2006-06-26 00:27:38 -0700 | [diff] [blame] | 121 | config MD_RAID456 |
| 122 | tristate "RAID-4/RAID-5/RAID-6 mode" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | depends on BLK_DEV_MD |
Dan Williams | 9bc89cd | 2007-01-02 11:10:44 -0700 | [diff] [blame] | 124 | select ASYNC_MEMCPY |
| 125 | select ASYNC_XOR |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | ---help--- |
| 127 | A RAID-5 set of N drives with a capacity of C MB per drive provides |
| 128 | the capacity of C * (N - 1) MB, and protects against a failure |
| 129 | of a single drive. For a given sector (row) number, (N - 1) drives |
| 130 | contain data sectors, and one drive contains the parity protection. |
| 131 | For a RAID-4 set, the parity blocks are present on a single drive, |
| 132 | while a RAID-5 set distributes the parity across the drives in one |
| 133 | of the available parity distribution methods. |
| 134 | |
NeilBrown | 16a53ec | 2006-06-26 00:27:38 -0700 | [diff] [blame] | 135 | A RAID-6 set of N drives with a capacity of C MB per drive |
| 136 | provides the capacity of C * (N - 2) MB, and protects |
| 137 | against a failure of any two drives. For a given sector |
| 138 | (row) number, (N - 2) drives contain data sectors, and two |
| 139 | drives contains two independent redundancy syndromes. Like |
| 140 | RAID-5, RAID-6 distributes the syndromes across the drives |
| 141 | in one of the available parity distribution methods. |
| 142 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | Information about Software RAID on Linux is contained in the |
| 144 | Software-RAID mini-HOWTO, available from |
| 145 | <http://www.tldp.org/docs.html#howto>. There you will also |
| 146 | learn where to get the supporting user space utilities raidtools. |
| 147 | |
NeilBrown | 16a53ec | 2006-06-26 00:27:38 -0700 | [diff] [blame] | 148 | If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | compile this code as a module, choose M here: the module |
NeilBrown | 16a53ec | 2006-06-26 00:27:38 -0700 | [diff] [blame] | 150 | will be called raid456. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | |
| 152 | If unsure, say Y. |
| 153 | |
NeilBrown | 2926955 | 2006-03-27 01:18:10 -0800 | [diff] [blame] | 154 | config MD_RAID5_RESHAPE |
NeilBrown | 14f50b4 | 2006-10-03 01:16:00 -0700 | [diff] [blame] | 155 | bool "Support adding drives to a raid-5 array" |
| 156 | depends on MD_RAID456 |
| 157 | default y |
NeilBrown | 2926955 | 2006-03-27 01:18:10 -0800 | [diff] [blame] | 158 | ---help--- |
| 159 | A RAID-5 set can be expanded by adding extra drives. This |
| 160 | requires "restriping" the array which means (almost) every |
| 161 | block must be written to a different place. |
| 162 | |
| 163 | This option allows such restriping to be done while the array |
NeilBrown | 14f50b4 | 2006-10-03 01:16:00 -0700 | [diff] [blame] | 164 | is online. |
NeilBrown | 2926955 | 2006-03-27 01:18:10 -0800 | [diff] [blame] | 165 | |
Justin Piszcz | 4d2554d | 2006-06-26 00:27:50 -0700 | [diff] [blame] | 166 | You will need mdadm version 2.4.1 or later to use this |
NeilBrown | 6f91fe8 | 2006-04-10 22:52:48 -0700 | [diff] [blame] | 167 | feature safely. During the early stage of reshape there is |
| 168 | a critical section where live data is being over-written. A |
| 169 | crash during this time needs extra care for recovery. The |
| 170 | newer mdadm takes a copy of the data in the critical section |
| 171 | and will restore it, if necessary, after a crash. |
NeilBrown | 2926955 | 2006-03-27 01:18:10 -0800 | [diff] [blame] | 172 | |
| 173 | The mdadm usage is e.g. |
| 174 | mdadm --grow /dev/md1 --raid-disks=6 |
| 175 | to grow '/dev/md1' to having 6 disks. |
| 176 | |
| 177 | Note: The array can only be expanded, not contracted. |
| 178 | There should be enough spares already present to make the new |
| 179 | array workable. |
| 180 | |
NeilBrown | 14f50b4 | 2006-10-03 01:16:00 -0700 | [diff] [blame] | 181 | If unsure, say Y. |
| 182 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | config MD_MULTIPATH |
| 184 | tristate "Multipath I/O support" |
| 185 | depends on BLK_DEV_MD |
| 186 | help |
| 187 | Multipath-IO is the ability of certain devices to address the same |
| 188 | physical disk over multiple 'IO paths'. The code ensures that such |
| 189 | paths can be defined and handled at runtime, and ensures that a |
| 190 | transparent failover to the backup path(s) happens if a IO errors |
| 191 | arrives on the primary path. |
| 192 | |
| 193 | If unsure, say N. |
| 194 | |
| 195 | config MD_FAULTY |
| 196 | tristate "Faulty test module for MD" |
| 197 | depends on BLK_DEV_MD |
| 198 | help |
| 199 | The "faulty" module allows for a block device that occasionally returns |
| 200 | read or write errors. It is useful for testing. |
| 201 | |
| 202 | In unsure, say N. |
| 203 | |
| 204 | config BLK_DEV_DM |
| 205 | tristate "Device mapper support" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | ---help--- |
| 207 | Device-mapper is a low level volume manager. It works by allowing |
| 208 | people to specify mappings for ranges of logical sectors. Various |
| 209 | mapping types are available, in addition people may write their own |
| 210 | modules containing custom mappings if they wish. |
| 211 | |
| 212 | Higher level volume managers such as LVM2 use this driver. |
| 213 | |
| 214 | To compile this as a module, choose M here: the module will be |
| 215 | called dm-mod. |
| 216 | |
| 217 | If unsure, say N. |
| 218 | |
Bryn Reeves | cc10920 | 2006-10-03 01:15:35 -0700 | [diff] [blame] | 219 | config DM_DEBUG |
| 220 | boolean "Device mapper debugging support" |
Alasdair G Kergon | 0149e57 | 2008-02-08 02:10:32 +0000 | [diff] [blame] | 221 | depends on BLK_DEV_DM |
Bryn Reeves | cc10920 | 2006-10-03 01:15:35 -0700 | [diff] [blame] | 222 | ---help--- |
| 223 | Enable this for messages that may help debug device-mapper problems. |
| 224 | |
| 225 | If unsure, say N. |
| 226 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | config DM_CRYPT |
| 228 | tristate "Crypt target support" |
Alasdair G Kergon | 0149e57 | 2008-02-08 02:10:32 +0000 | [diff] [blame] | 229 | depends on BLK_DEV_DM |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | select CRYPTO |
Herbert Xu | 3263263 | 2006-12-10 09:50:36 +1100 | [diff] [blame] | 231 | select CRYPTO_CBC |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | ---help--- |
| 233 | This device-mapper target allows you to create a device that |
| 234 | transparently encrypts the data on it. You'll need to activate |
| 235 | the ciphers you're going to use in the cryptoapi configuration. |
| 236 | |
| 237 | Information on how to use dm-crypt can be found on |
| 238 | |
| 239 | <http://www.saout.de/misc/dm-crypt/> |
| 240 | |
| 241 | To compile this code as a module, choose M here: the module will |
| 242 | be called dm-crypt. |
| 243 | |
| 244 | If unsure, say N. |
| 245 | |
| 246 | config DM_SNAPSHOT |
Alasdair G Kergon | 0149e57 | 2008-02-08 02:10:32 +0000 | [diff] [blame] | 247 | tristate "Snapshot target" |
| 248 | depends on BLK_DEV_DM |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | ---help--- |
Justin Piszcz | 4d2554d | 2006-06-26 00:27:50 -0700 | [diff] [blame] | 250 | Allow volume managers to take writable snapshots of a device. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | |
| 252 | config DM_MIRROR |
Alasdair G Kergon | 0149e57 | 2008-02-08 02:10:32 +0000 | [diff] [blame] | 253 | tristate "Mirror target" |
| 254 | depends on BLK_DEV_DM |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | ---help--- |
| 256 | Allow volume managers to mirror logical volumes, also |
| 257 | needed for live data migration tools such as 'pvmove'. |
| 258 | |
| 259 | config DM_ZERO |
Alasdair G Kergon | 0149e57 | 2008-02-08 02:10:32 +0000 | [diff] [blame] | 260 | tristate "Zero target" |
| 261 | depends on BLK_DEV_DM |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | ---help--- |
| 263 | A target that discards writes, and returns all zeroes for |
| 264 | reads. Useful in some recovery situations. |
| 265 | |
| 266 | config DM_MULTIPATH |
Alasdair G Kergon | 0149e57 | 2008-02-08 02:10:32 +0000 | [diff] [blame] | 267 | tristate "Multipath target" |
| 268 | depends on BLK_DEV_DM |
Chandra Seetharaman | fe9233f | 2008-05-23 18:16:40 -0700 | [diff] [blame] | 269 | # nasty syntax but means make DM_MULTIPATH independent |
| 270 | # of SCSI_DH if the latter isn't defined but if |
| 271 | # it is, DM_MULTIPATH must depend on it. We get a build |
| 272 | # error if SCSI_DH=m and DM_MULTIPATH=y |
| 273 | depends on SCSI_DH || !SCSI_DH |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | ---help--- |
| 275 | Allow volume managers to support multipath hardware. |
| 276 | |
Heinz Mauelshagen | 26b9f22 | 2007-05-09 02:33:06 -0700 | [diff] [blame] | 277 | config DM_DELAY |
| 278 | tristate "I/O delaying target (EXPERIMENTAL)" |
| 279 | depends on BLK_DEV_DM && EXPERIMENTAL |
| 280 | ---help--- |
| 281 | A target that delays reads and/or writes and can send |
| 282 | them to different devices. Useful for testing. |
| 283 | |
| 284 | If unsure, say N. |
| 285 | |
Mike Anderson | 51e5b2b | 2007-10-19 22:48:00 +0100 | [diff] [blame] | 286 | config DM_UEVENT |
| 287 | bool "DM uevents (EXPERIMENTAL)" |
| 288 | depends on BLK_DEV_DM && EXPERIMENTAL |
| 289 | ---help--- |
| 290 | Generate udev events for DM events. |
| 291 | |
Jan Engelhardt | afd4403 | 2007-07-17 04:06:11 -0700 | [diff] [blame] | 292 | endif # MD |