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. 177 178 179config MD_CLUSTER 180 tristate "Cluster Support for MD (EXPERIMENTAL)" 181 depends on BLK_DEV_MD 182 depends on DLM 183 default n 184 ---help--- 185 Clustering support for MD devices. This enables locking and 186 synchronization across multiple systems on the cluster, so all 187 nodes in the cluster can access the MD devices simultaneously. 188 189 This brings the redundancy (and uptime) of RAID levels across the 190 nodes of the cluster. 191 192 If unsure, say N. 193 194source "drivers/md/bcache/Kconfig" 195 196config BLK_DEV_DM_BUILTIN 197 bool 198 199config BLK_DEV_DM 200 tristate "Device mapper support" 201 select BLK_DEV_DM_BUILTIN 202 ---help--- 203 Device-mapper is a low level volume manager. It works by allowing 204 people to specify mappings for ranges of logical sectors. Various 205 mapping types are available, in addition people may write their own 206 modules containing custom mappings if they wish. 207 208 Higher level volume managers such as LVM2 use this driver. 209 210 To compile this as a module, choose M here: the module will be 211 called dm-mod. 212 213 If unsure, say N. 214 215config DM_MQ_DEFAULT 216 bool "request-based DM: use blk-mq I/O path by default" 217 depends on BLK_DEV_DM 218 ---help--- 219 This option enables the blk-mq based I/O path for request-based 220 DM devices by default. With the option the dm_mod.use_blk_mq 221 module/boot option defaults to Y, without it to N, but it can 222 still be overriden either way. 223 224 If unsure say N. 225 226config DM_DEBUG 227 bool "Device mapper debugging support" 228 depends on BLK_DEV_DM 229 ---help--- 230 Enable this for messages that may help debug device-mapper problems. 231 232 If unsure, say N. 233 234config DM_BUFIO 235 tristate 236 depends on BLK_DEV_DM 237 ---help--- 238 This interface allows you to do buffered I/O on a device and acts 239 as a cache, holding recently-read blocks in memory and performing 240 delayed writes. 241 242config DM_BIO_PRISON 243 tristate 244 depends on BLK_DEV_DM 245 ---help--- 246 Some bio locking schemes used by other device-mapper targets 247 including thin provisioning. 248 249source "drivers/md/persistent-data/Kconfig" 250 251config DM_CRYPT 252 tristate "Crypt target support" 253 depends on BLK_DEV_DM 254 select CRYPTO 255 select CRYPTO_CBC 256 ---help--- 257 This device-mapper target allows you to create a device that 258 transparently encrypts the data on it. You'll need to activate 259 the ciphers you're going to use in the cryptoapi configuration. 260 261 For further information on dm-crypt and userspace tools see: 262 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt> 263 264 To compile this code as a module, choose M here: the module will 265 be called dm-crypt. 266 267 If unsure, say N. 268 269config DM_SNAPSHOT 270 tristate "Snapshot target" 271 depends on BLK_DEV_DM 272 select DM_BUFIO 273 ---help--- 274 Allow volume managers to take writable snapshots of a device. 275 276config DM_THIN_PROVISIONING 277 tristate "Thin provisioning target" 278 depends on BLK_DEV_DM 279 select DM_PERSISTENT_DATA 280 select DM_BIO_PRISON 281 ---help--- 282 Provides thin provisioning and snapshots that share a data store. 283 284config DM_CACHE 285 tristate "Cache target (EXPERIMENTAL)" 286 depends on BLK_DEV_DM 287 default n 288 select DM_PERSISTENT_DATA 289 select DM_BIO_PRISON 290 ---help--- 291 dm-cache attempts to improve performance of a block device by 292 moving frequently used data to a smaller, higher performance 293 device. Different 'policy' plugins can be used to change the 294 algorithms used to select which blocks are promoted, demoted, 295 cleaned etc. It supports writeback and writethrough modes. 296 297config DM_CACHE_MQ 298 tristate "MQ Cache Policy (EXPERIMENTAL)" 299 depends on DM_CACHE 300 default y 301 ---help--- 302 A cache policy that uses a multiqueue ordered by recent hit 303 count to select which blocks should be promoted and demoted. 304 This is meant to be a general purpose policy. It prioritises 305 reads over writes. 306 307config DM_CACHE_SMQ 308 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)" 309 depends on DM_CACHE 310 default y 311 ---help--- 312 A cache policy that uses a multiqueue ordered by recent hits 313 to select which blocks should be promoted and demoted. 314 This is meant to be a general purpose policy. It prioritises 315 reads over writes. This SMQ policy (vs MQ) offers the promise 316 of less memory utilization, improved performance and increased 317 adaptability in the face of changing workloads. 318 319config DM_CACHE_CLEANER 320 tristate "Cleaner Cache Policy (EXPERIMENTAL)" 321 depends on DM_CACHE 322 default y 323 ---help--- 324 A simple cache policy that writes back all data to the 325 origin. Used when decommissioning a dm-cache. 326 327config DM_ERA 328 tristate "Era target (EXPERIMENTAL)" 329 depends on BLK_DEV_DM 330 default n 331 select DM_PERSISTENT_DATA 332 select DM_BIO_PRISON 333 ---help--- 334 dm-era tracks which parts of a block device are written to 335 over time. Useful for maintaining cache coherency when using 336 vendor snapshots. 337 338config DM_MIRROR 339 tristate "Mirror target" 340 depends on BLK_DEV_DM 341 ---help--- 342 Allow volume managers to mirror logical volumes, also 343 needed for live data migration tools such as 'pvmove'. 344 345config DM_LOG_USERSPACE 346 tristate "Mirror userspace logging" 347 depends on DM_MIRROR && NET 348 select CONNECTOR 349 ---help--- 350 The userspace logging module provides a mechanism for 351 relaying the dm-dirty-log API to userspace. Log designs 352 which are more suited to userspace implementation (e.g. 353 shared storage logs) or experimental logs can be implemented 354 by leveraging this framework. 355 356config DM_RAID 357 tristate "RAID 1/4/5/6/10 target" 358 depends on BLK_DEV_DM 359 select MD_RAID1 360 select MD_RAID10 361 select MD_RAID456 362 select BLK_DEV_MD 363 ---help--- 364 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings 365 366 A RAID-5 set of N drives with a capacity of C MB per drive provides 367 the capacity of C * (N - 1) MB, and protects against a failure 368 of a single drive. For a given sector (row) number, (N - 1) drives 369 contain data sectors, and one drive contains the parity protection. 370 For a RAID-4 set, the parity blocks are present on a single drive, 371 while a RAID-5 set distributes the parity across the drives in one 372 of the available parity distribution methods. 373 374 A RAID-6 set of N drives with a capacity of C MB per drive 375 provides the capacity of C * (N - 2) MB, and protects 376 against a failure of any two drives. For a given sector 377 (row) number, (N - 2) drives contain data sectors, and two 378 drives contains two independent redundancy syndromes. Like 379 RAID-5, RAID-6 distributes the syndromes across the drives 380 in one of the available parity distribution methods. 381 382config DM_ZERO 383 tristate "Zero target" 384 depends on BLK_DEV_DM 385 ---help--- 386 A target that discards writes, and returns all zeroes for 387 reads. Useful in some recovery situations. 388 389config DM_MULTIPATH 390 tristate "Multipath target" 391 depends on BLK_DEV_DM 392 # nasty syntax but means make DM_MULTIPATH independent 393 # of SCSI_DH if the latter isn't defined but if 394 # it is, DM_MULTIPATH must depend on it. We get a build 395 # error if SCSI_DH=m and DM_MULTIPATH=y 396 depends on !SCSI_DH || SCSI 397 ---help--- 398 Allow volume managers to support multipath hardware. 399 400config DM_MULTIPATH_QL 401 tristate "I/O Path Selector based on the number of in-flight I/Os" 402 depends on DM_MULTIPATH 403 ---help--- 404 This path selector is a dynamic load balancer which selects 405 the path with the least number of in-flight I/Os. 406 407 If unsure, say N. 408 409config DM_MULTIPATH_ST 410 tristate "I/O Path Selector based on the service time" 411 depends on DM_MULTIPATH 412 ---help--- 413 This path selector is a dynamic load balancer which selects 414 the path expected to complete the incoming I/O in the shortest 415 time. 416 417 If unsure, say N. 418 419config DM_DELAY 420 tristate "I/O delaying target" 421 depends on BLK_DEV_DM 422 ---help--- 423 A target that delays reads and/or writes and can send 424 them to different devices. Useful for testing. 425 426 If unsure, say N. 427 428config DM_UEVENT 429 bool "DM uevents" 430 depends on BLK_DEV_DM 431 ---help--- 432 Generate udev events for DM events. 433 434config DM_FLAKEY 435 tristate "Flakey target" 436 depends on BLK_DEV_DM 437 ---help--- 438 A target that intermittently fails I/O for debugging purposes. 439 440config DM_VERITY 441 tristate "Verity target support" 442 depends on BLK_DEV_DM 443 select CRYPTO 444 select CRYPTO_HASH 445 select DM_BUFIO 446 ---help--- 447 This device-mapper target creates a read-only device that 448 transparently validates the data on one underlying device against 449 a pre-generated tree of cryptographic checksums stored on a second 450 device. 451 452 You'll need to activate the digests you're going to use in the 453 cryptoapi configuration. 454 455 To compile this code as a module, choose M here: the module will 456 be called dm-verity. 457 458 If unsure, say N. 459 460config DM_SWITCH 461 tristate "Switch target support (EXPERIMENTAL)" 462 depends on BLK_DEV_DM 463 ---help--- 464 This device-mapper target creates a device that supports an arbitrary 465 mapping of fixed-size regions of I/O across a fixed set of paths. 466 The path used for any specific region can be switched dynamically 467 by sending the target a message. 468 469 To compile this code as a module, choose M here: the module will 470 be called dm-switch. 471 472 If unsure, say N. 473 474config DM_LOG_WRITES 475 tristate "Log writes target support" 476 depends on BLK_DEV_DM 477 ---help--- 478 This device-mapper target takes two devices, one device to use 479 normally, one to log all write operations done to the first device. 480 This is for use by file system developers wishing to verify that 481 their fs is writing a consistent file system at all times by allowing 482 them to replay the log in a variety of ways and to check the 483 contents. 484 485 To compile this code as a module, choose M here: the module will 486 be called dm-log-writes. 487 488 If unsure, say N. 489 490endif # MD 491