1# 2# Block device driver configuration 3# 4 5menuconfig MD 6 bool "Multiple devices driver support (RAID and LVM)" 7 depends on BLOCK 8 select SRCU 9 help 10 Support multiple physical spindles through a single logical device. 11 Required for RAID and logical volume management. 12 13if MD 14 15config BLK_DEV_MD 16 tristate "RAID support" 17 ---help--- 18 This driver lets you combine several hard disk partitions into one 19 logical block device. This can be used to simply append one 20 partition to another one or to combine several redundant hard disks 21 into a RAID1/4/5 device so as to provide protection against hard 22 disk failures. This is called "Software RAID" since the combining of 23 the partitions is done by the kernel. "Hardware RAID" means that the 24 combining is done by a dedicated controller; if you have such a 25 controller, you do not need to say Y here. 26 27 More information about Software RAID on Linux is contained in the 28 Software RAID mini-HOWTO, available from 29 <http://www.tldp.org/docs.html#howto>. There you will also learn 30 where to get the supporting user space utilities raidtools. 31 32 If unsure, say N. 33 34config MD_AUTODETECT 35 bool "Autodetect RAID arrays during kernel boot" 36 depends on BLK_DEV_MD=y 37 default y 38 ---help--- 39 If you say Y here, then the kernel will try to autodetect raid 40 arrays as part of its boot process. 41 42 If you don't use raid and say Y, this autodetection can cause 43 a several-second delay in the boot time due to various 44 synchronisation steps that are part of this step. 45 46 If unsure, say Y. 47 48config MD_LINEAR 49 tristate "Linear (append) mode" 50 depends on BLK_DEV_MD 51 ---help--- 52 If you say Y here, then your multiple devices driver will be able to 53 use the so-called linear mode, i.e. it will combine the hard disk 54 partitions by simply appending one to the other. 55 56 To compile this as a module, choose M here: the module 57 will be called linear. 58 59 If unsure, say Y. 60 61config MD_RAID0 62 tristate "RAID-0 (striping) mode" 63 depends on BLK_DEV_MD 64 ---help--- 65 If you say Y here, then your multiple devices driver will be able to 66 use the so-called raid0 mode, i.e. it will combine the hard disk 67 partitions into one logical device in such a fashion as to fill them 68 up evenly, one chunk here and one chunk there. This will increase 69 the throughput rate if the partitions reside on distinct disks. 70 71 Information about Software RAID on Linux is contained in the 72 Software-RAID mini-HOWTO, available from 73 <http://www.tldp.org/docs.html#howto>. There you will also 74 learn where to get the supporting user space utilities raidtools. 75 76 To compile this as a module, choose M here: the module 77 will be called raid0. 78 79 If unsure, say Y. 80 81config MD_RAID1 82 tristate "RAID-1 (mirroring) mode" 83 depends on BLK_DEV_MD 84 ---help--- 85 A RAID-1 set consists of several disk drives which are exact copies 86 of each other. In the event of a mirror failure, the RAID driver 87 will continue to use the operational mirrors in the set, providing 88 an error free MD (multiple device) to the higher levels of the 89 kernel. In a set with N drives, the available space is the capacity 90 of a single drive, and the set protects against a failure of (N - 1) 91 drives. 92 93 Information about Software RAID on Linux is contained in the 94 Software-RAID mini-HOWTO, available from 95 <http://www.tldp.org/docs.html#howto>. There you will also 96 learn where to get the supporting user space utilities raidtools. 97 98 If you want to use such a RAID-1 set, say Y. To compile this code 99 as a module, choose M here: the module will be called raid1. 100 101 If unsure, say Y. 102 103config MD_RAID10 104 tristate "RAID-10 (mirrored striping) mode" 105 depends on BLK_DEV_MD 106 ---help--- 107 RAID-10 provides a combination of striping (RAID-0) and 108 mirroring (RAID-1) with easier configuration and more flexible 109 layout. 110 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to 111 be the same size (or at least, only as much as the smallest device 112 will be used). 113 RAID-10 provides a variety of layouts that provide different levels 114 of redundancy and performance. 115 116 RAID-10 requires mdadm-1.7.0 or later, available at: 117 118 ftp://ftp.kernel.org/pub/linux/utils/raid/mdadm/ 119 120 If unsure, say Y. 121 122config MD_RAID456 123 tristate "RAID-4/RAID-5/RAID-6 mode" 124 depends on BLK_DEV_MD 125 select RAID6_PQ 126 select ASYNC_MEMCPY 127 select ASYNC_XOR 128 select ASYNC_PQ 129 select ASYNC_RAID6_RECOV 130 ---help--- 131 A RAID-5 set of N drives with a capacity of C MB per drive provides 132 the capacity of C * (N - 1) MB, and protects against a failure 133 of a single drive. For a given sector (row) number, (N - 1) drives 134 contain data sectors, and one drive contains the parity protection. 135 For a RAID-4 set, the parity blocks are present on a single drive, 136 while a RAID-5 set distributes the parity across the drives in one 137 of the available parity distribution methods. 138 139 A RAID-6 set of N drives with a capacity of C MB per drive 140 provides the capacity of C * (N - 2) MB, and protects 141 against a failure of any two drives. For a given sector 142 (row) number, (N - 2) drives contain data sectors, and two 143 drives contains two independent redundancy syndromes. Like 144 RAID-5, RAID-6 distributes the syndromes across the drives 145 in one of the available parity distribution methods. 146 147 Information about Software RAID on Linux is contained in the 148 Software-RAID mini-HOWTO, available from 149 <http://www.tldp.org/docs.html#howto>. There you will also 150 learn where to get the supporting user space utilities raidtools. 151 152 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To 153 compile this code as a module, choose M here: the module 154 will be called raid456. 155 156 If unsure, say Y. 157 158config MD_MULTIPATH 159 tristate "Multipath I/O support" 160 depends on BLK_DEV_MD 161 help 162 MD_MULTIPATH provides a simple multi-path personality for use 163 the MD framework. It is not under active development. New 164 projects should consider using DM_MULTIPATH which has more 165 features and more testing. 166 167 If unsure, say N. 168 169config MD_FAULTY 170 tristate "Faulty test module for MD" 171 depends on BLK_DEV_MD 172 help 173 The "faulty" module allows for a block device that occasionally returns 174 read or write errors. It is useful for testing. 175 176 In unsure, say N. 177 178source "drivers/md/bcache/Kconfig" 179 180config BLK_DEV_DM_BUILTIN 181 bool 182 183config BLK_DEV_DM 184 tristate "Device mapper support" 185 select BLK_DEV_DM_BUILTIN 186 ---help--- 187 Device-mapper is a low level volume manager. It works by allowing 188 people to specify mappings for ranges of logical sectors. Various 189 mapping types are available, in addition people may write their own 190 modules containing custom mappings if they wish. 191 192 Higher level volume managers such as LVM2 use this driver. 193 194 To compile this as a module, choose M here: the module will be 195 called dm-mod. 196 197 If unsure, say N. 198 199config DM_MQ_DEFAULT 200 bool "request-based DM: use blk-mq I/O path by default" 201 depends on BLK_DEV_DM 202 ---help--- 203 This option enables the blk-mq based I/O path for request-based 204 DM devices by default. With the option the dm_mod.use_blk_mq 205 module/boot option defaults to Y, without it to N, but it can 206 still be overriden either way. 207 208 If unsure say N. 209 210config DM_DEBUG 211 bool "Device mapper debugging support" 212 depends on BLK_DEV_DM 213 ---help--- 214 Enable this for messages that may help debug device-mapper problems. 215 216 If unsure, say N. 217 218config DM_BUFIO 219 tristate 220 depends on BLK_DEV_DM 221 ---help--- 222 This interface allows you to do buffered I/O on a device and acts 223 as a cache, holding recently-read blocks in memory and performing 224 delayed writes. 225 226config DM_BIO_PRISON 227 tristate 228 depends on BLK_DEV_DM 229 ---help--- 230 Some bio locking schemes used by other device-mapper targets 231 including thin provisioning. 232 233source "drivers/md/persistent-data/Kconfig" 234 235config DM_CRYPT 236 tristate "Crypt target support" 237 depends on BLK_DEV_DM 238 select CRYPTO 239 select CRYPTO_CBC 240 ---help--- 241 This device-mapper target allows you to create a device that 242 transparently encrypts the data on it. You'll need to activate 243 the ciphers you're going to use in the cryptoapi configuration. 244 245 For further information on dm-crypt and userspace tools see: 246 <http://code.google.com/p/cryptsetup/wiki/DMCrypt> 247 248 To compile this code as a module, choose M here: the module will 249 be called dm-crypt. 250 251 If unsure, say N. 252 253config DM_SNAPSHOT 254 tristate "Snapshot target" 255 depends on BLK_DEV_DM 256 select DM_BUFIO 257 ---help--- 258 Allow volume managers to take writable snapshots of a device. 259 260config DM_THIN_PROVISIONING 261 tristate "Thin provisioning target" 262 depends on BLK_DEV_DM 263 select DM_PERSISTENT_DATA 264 select DM_BIO_PRISON 265 ---help--- 266 Provides thin provisioning and snapshots that share a data store. 267 268config DM_CACHE 269 tristate "Cache target (EXPERIMENTAL)" 270 depends on BLK_DEV_DM 271 default n 272 select DM_PERSISTENT_DATA 273 select DM_BIO_PRISON 274 ---help--- 275 dm-cache attempts to improve performance of a block device by 276 moving frequently used data to a smaller, higher performance 277 device. Different 'policy' plugins can be used to change the 278 algorithms used to select which blocks are promoted, demoted, 279 cleaned etc. It supports writeback and writethrough modes. 280 281config DM_CACHE_MQ 282 tristate "MQ Cache Policy (EXPERIMENTAL)" 283 depends on DM_CACHE 284 default y 285 ---help--- 286 A cache policy that uses a multiqueue ordered by recent hit 287 count to select which blocks should be promoted and demoted. 288 This is meant to be a general purpose policy. It prioritises 289 reads over writes. 290 291config DM_CACHE_CLEANER 292 tristate "Cleaner Cache Policy (EXPERIMENTAL)" 293 depends on DM_CACHE 294 default y 295 ---help--- 296 A simple cache policy that writes back all data to the 297 origin. Used when decommissioning a dm-cache. 298 299config DM_ERA 300 tristate "Era target (EXPERIMENTAL)" 301 depends on BLK_DEV_DM 302 default n 303 select DM_PERSISTENT_DATA 304 select DM_BIO_PRISON 305 ---help--- 306 dm-era tracks which parts of a block device are written to 307 over time. Useful for maintaining cache coherency when using 308 vendor snapshots. 309 310config DM_MIRROR 311 tristate "Mirror target" 312 depends on BLK_DEV_DM 313 ---help--- 314 Allow volume managers to mirror logical volumes, also 315 needed for live data migration tools such as 'pvmove'. 316 317config DM_LOG_USERSPACE 318 tristate "Mirror userspace logging" 319 depends on DM_MIRROR && NET 320 select CONNECTOR 321 ---help--- 322 The userspace logging module provides a mechanism for 323 relaying the dm-dirty-log API to userspace. Log designs 324 which are more suited to userspace implementation (e.g. 325 shared storage logs) or experimental logs can be implemented 326 by leveraging this framework. 327 328config DM_RAID 329 tristate "RAID 1/4/5/6/10 target" 330 depends on BLK_DEV_DM 331 select MD_RAID1 332 select MD_RAID10 333 select MD_RAID456 334 select BLK_DEV_MD 335 ---help--- 336 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings 337 338 A RAID-5 set of N drives with a capacity of C MB per drive provides 339 the capacity of C * (N - 1) MB, and protects against a failure 340 of a single drive. For a given sector (row) number, (N - 1) drives 341 contain data sectors, and one drive contains the parity protection. 342 For a RAID-4 set, the parity blocks are present on a single drive, 343 while a RAID-5 set distributes the parity across the drives in one 344 of the available parity distribution methods. 345 346 A RAID-6 set of N drives with a capacity of C MB per drive 347 provides the capacity of C * (N - 2) MB, and protects 348 against a failure of any two drives. For a given sector 349 (row) number, (N - 2) drives contain data sectors, and two 350 drives contains two independent redundancy syndromes. Like 351 RAID-5, RAID-6 distributes the syndromes across the drives 352 in one of the available parity distribution methods. 353 354config DM_ZERO 355 tristate "Zero target" 356 depends on BLK_DEV_DM 357 ---help--- 358 A target that discards writes, and returns all zeroes for 359 reads. Useful in some recovery situations. 360 361config DM_MULTIPATH 362 tristate "Multipath target" 363 depends on BLK_DEV_DM 364 # nasty syntax but means make DM_MULTIPATH independent 365 # of SCSI_DH if the latter isn't defined but if 366 # it is, DM_MULTIPATH must depend on it. We get a build 367 # error if SCSI_DH=m and DM_MULTIPATH=y 368 depends on SCSI_DH || !SCSI_DH 369 ---help--- 370 Allow volume managers to support multipath hardware. 371 372config DM_MULTIPATH_QL 373 tristate "I/O Path Selector based on the number of in-flight I/Os" 374 depends on DM_MULTIPATH 375 ---help--- 376 This path selector is a dynamic load balancer which selects 377 the path with the least number of in-flight I/Os. 378 379 If unsure, say N. 380 381config DM_MULTIPATH_ST 382 tristate "I/O Path Selector based on the service time" 383 depends on DM_MULTIPATH 384 ---help--- 385 This path selector is a dynamic load balancer which selects 386 the path expected to complete the incoming I/O in the shortest 387 time. 388 389 If unsure, say N. 390 391config DM_DELAY 392 tristate "I/O delaying target" 393 depends on BLK_DEV_DM 394 ---help--- 395 A target that delays reads and/or writes and can send 396 them to different devices. Useful for testing. 397 398 If unsure, say N. 399 400config DM_UEVENT 401 bool "DM uevents" 402 depends on BLK_DEV_DM 403 ---help--- 404 Generate udev events for DM events. 405 406config DM_FLAKEY 407 tristate "Flakey target" 408 depends on BLK_DEV_DM 409 ---help--- 410 A target that intermittently fails I/O for debugging purposes. 411 412config DM_VERITY 413 tristate "Verity target support" 414 depends on BLK_DEV_DM 415 select CRYPTO 416 select CRYPTO_HASH 417 select DM_BUFIO 418 ---help--- 419 This device-mapper target creates a read-only device that 420 transparently validates the data on one underlying device against 421 a pre-generated tree of cryptographic checksums stored on a second 422 device. 423 424 You'll need to activate the digests you're going to use in the 425 cryptoapi configuration. 426 427 To compile this code as a module, choose M here: the module will 428 be called dm-verity. 429 430 If unsure, say N. 431 432config DM_SWITCH 433 tristate "Switch target support (EXPERIMENTAL)" 434 depends on BLK_DEV_DM 435 ---help--- 436 This device-mapper target creates a device that supports an arbitrary 437 mapping of fixed-size regions of I/O across a fixed set of paths. 438 The path used for any specific region can be switched dynamically 439 by sending the target a message. 440 441 To compile this code as a module, choose M here: the module will 442 be called dm-switch. 443 444 If unsure, say N. 445 446config DM_LOG_WRITES 447 tristate "Log writes target support" 448 depends on BLK_DEV_DM 449 ---help--- 450 This device-mapper target takes two devices, one device to use 451 normally, one to log all write operations done to the first device. 452 This is for use by file system developers wishing to verify that 453 their fs is writing a consitent file system at all times by allowing 454 them to replay the log in a variety of ways and to check the 455 contents. 456 457 To compile this code as a module, choose M here: the module will 458 be called dm-log-writes. 459 460 If unsure, say N. 461 462endif # MD 463