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 LIBCRC32C 127 select ASYNC_MEMCPY 128 select ASYNC_XOR 129 select ASYNC_PQ 130 select ASYNC_RAID6_RECOV 131 ---help--- 132 A RAID-5 set of N drives with a capacity of C MB per drive provides 133 the capacity of C * (N - 1) MB, and protects against a failure 134 of a single drive. For a given sector (row) number, (N - 1) drives 135 contain data sectors, and one drive contains the parity protection. 136 For a RAID-4 set, the parity blocks are present on a single drive, 137 while a RAID-5 set distributes the parity across the drives in one 138 of the available parity distribution methods. 139 140 A RAID-6 set of N drives with a capacity of C MB per drive 141 provides the capacity of C * (N - 2) MB, and protects 142 against a failure of any two drives. For a given sector 143 (row) number, (N - 2) drives contain data sectors, and two 144 drives contains two independent redundancy syndromes. Like 145 RAID-5, RAID-6 distributes the syndromes across the drives 146 in one of the available parity distribution methods. 147 148 Information about Software RAID on Linux is contained in the 149 Software-RAID mini-HOWTO, available from 150 <http://www.tldp.org/docs.html#howto>. There you will also 151 learn where to get the supporting user space utilities raidtools. 152 153 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To 154 compile this code as a module, choose M here: the module 155 will be called raid456. 156 157 If unsure, say Y. 158 159config MD_MULTIPATH 160 tristate "Multipath I/O support" 161 depends on BLK_DEV_MD 162 help 163 MD_MULTIPATH provides a simple multi-path personality for use 164 the MD framework. It is not under active development. New 165 projects should consider using DM_MULTIPATH which has more 166 features and more testing. 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. 178 179 180config MD_CLUSTER 181 tristate "Cluster Support for MD (EXPERIMENTAL)" 182 depends on BLK_DEV_MD 183 depends on DLM 184 default n 185 ---help--- 186 Clustering support for MD devices. This enables locking and 187 synchronization across multiple systems on the cluster, so all 188 nodes in the cluster can access the MD devices simultaneously. 189 190 This brings the redundancy (and uptime) of RAID levels across the 191 nodes of the cluster. 192 193 If unsure, say N. 194 195source "drivers/md/bcache/Kconfig" 196 197config BLK_DEV_DM_BUILTIN 198 bool 199 200config BLK_DEV_DM 201 tristate "Device mapper support" 202 select BLK_DEV_DM_BUILTIN 203 ---help--- 204 Device-mapper is a low level volume manager. It works by allowing 205 people to specify mappings for ranges of logical sectors. Various 206 mapping types are available, in addition people may write their own 207 modules containing custom mappings if they wish. 208 209 Higher level volume managers such as LVM2 use this driver. 210 211 To compile this as a module, choose M here: the module will be 212 called dm-mod. 213 214 If unsure, say N. 215 216config DM_MQ_DEFAULT 217 bool "request-based DM: use blk-mq I/O path by default" 218 depends on BLK_DEV_DM 219 ---help--- 220 This option enables the blk-mq based I/O path for request-based 221 DM devices by default. With the option the dm_mod.use_blk_mq 222 module/boot option defaults to Y, without it to N, but it can 223 still be overriden either way. 224 225 If unsure say N. 226 227config DM_DEBUG 228 bool "Device mapper debugging support" 229 depends on BLK_DEV_DM 230 ---help--- 231 Enable this for messages that may help debug device-mapper problems. 232 233 If unsure, say N. 234 235config DM_BUFIO 236 tristate 237 depends on BLK_DEV_DM 238 ---help--- 239 This interface allows you to do buffered I/O on a device and acts 240 as a cache, holding recently-read blocks in memory and performing 241 delayed writes. 242 243config DM_DEBUG_BLOCK_STACK_TRACING 244 bool "Keep stack trace of persistent data block lock holders" 245 depends on STACKTRACE_SUPPORT && DM_BUFIO 246 select STACKTRACE 247 ---help--- 248 Enable this for messages that may help debug problems with the 249 block manager locking used by thin provisioning and caching. 250 251 If unsure, say N. 252config DM_BIO_PRISON 253 tristate 254 depends on BLK_DEV_DM 255 ---help--- 256 Some bio locking schemes used by other device-mapper targets 257 including thin provisioning. 258 259source "drivers/md/persistent-data/Kconfig" 260 261config DM_CRYPT 262 tristate "Crypt target support" 263 depends on BLK_DEV_DM 264 select CRYPTO 265 select CRYPTO_CBC 266 ---help--- 267 This device-mapper target allows you to create a device that 268 transparently encrypts the data on it. You'll need to activate 269 the ciphers you're going to use in the cryptoapi configuration. 270 271 For further information on dm-crypt and userspace tools see: 272 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt> 273 274 To compile this code as a module, choose M here: the module will 275 be called dm-crypt. 276 277 If unsure, say N. 278 279config DM_SNAPSHOT 280 tristate "Snapshot target" 281 depends on BLK_DEV_DM 282 select DM_BUFIO 283 ---help--- 284 Allow volume managers to take writable snapshots of a device. 285 286config DM_THIN_PROVISIONING 287 tristate "Thin provisioning target" 288 depends on BLK_DEV_DM 289 select DM_PERSISTENT_DATA 290 select DM_BIO_PRISON 291 ---help--- 292 Provides thin provisioning and snapshots that share a data store. 293 294config DM_CACHE 295 tristate "Cache target (EXPERIMENTAL)" 296 depends on BLK_DEV_DM 297 default n 298 select DM_PERSISTENT_DATA 299 select DM_BIO_PRISON 300 ---help--- 301 dm-cache attempts to improve performance of a block device by 302 moving frequently used data to a smaller, higher performance 303 device. Different 'policy' plugins can be used to change the 304 algorithms used to select which blocks are promoted, demoted, 305 cleaned etc. It supports writeback and writethrough modes. 306 307config DM_CACHE_MQ 308 tristate "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 hit 313 count 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. 316 317config DM_CACHE_SMQ 318 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)" 319 depends on DM_CACHE 320 default y 321 ---help--- 322 A cache policy that uses a multiqueue ordered by recent hits 323 to select which blocks should be promoted and demoted. 324 This is meant to be a general purpose policy. It prioritises 325 reads over writes. This SMQ policy (vs MQ) offers the promise 326 of less memory utilization, improved performance and increased 327 adaptability in the face of changing workloads. 328 329config DM_CACHE_CLEANER 330 tristate "Cleaner Cache Policy (EXPERIMENTAL)" 331 depends on DM_CACHE 332 default y 333 ---help--- 334 A simple cache policy that writes back all data to the 335 origin. Used when decommissioning a dm-cache. 336 337config DM_ERA 338 tristate "Era target (EXPERIMENTAL)" 339 depends on BLK_DEV_DM 340 default n 341 select DM_PERSISTENT_DATA 342 select DM_BIO_PRISON 343 ---help--- 344 dm-era tracks which parts of a block device are written to 345 over time. Useful for maintaining cache coherency when using 346 vendor snapshots. 347 348config DM_MIRROR 349 tristate "Mirror target" 350 depends on BLK_DEV_DM 351 ---help--- 352 Allow volume managers to mirror logical volumes, also 353 needed for live data migration tools such as 'pvmove'. 354 355config DM_LOG_USERSPACE 356 tristate "Mirror userspace logging" 357 depends on DM_MIRROR && NET 358 select CONNECTOR 359 ---help--- 360 The userspace logging module provides a mechanism for 361 relaying the dm-dirty-log API to userspace. Log designs 362 which are more suited to userspace implementation (e.g. 363 shared storage logs) or experimental logs can be implemented 364 by leveraging this framework. 365 366config DM_RAID 367 tristate "RAID 1/4/5/6/10 target" 368 depends on BLK_DEV_DM 369 select MD_RAID1 370 select MD_RAID10 371 select MD_RAID456 372 select BLK_DEV_MD 373 ---help--- 374 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings 375 376 A RAID-5 set of N drives with a capacity of C MB per drive provides 377 the capacity of C * (N - 1) MB, and protects against a failure 378 of a single drive. For a given sector (row) number, (N - 1) drives 379 contain data sectors, and one drive contains the parity protection. 380 For a RAID-4 set, the parity blocks are present on a single drive, 381 while a RAID-5 set distributes the parity across the drives in one 382 of the available parity distribution methods. 383 384 A RAID-6 set of N drives with a capacity of C MB per drive 385 provides the capacity of C * (N - 2) MB, and protects 386 against a failure of any two drives. For a given sector 387 (row) number, (N - 2) drives contain data sectors, and two 388 drives contains two independent redundancy syndromes. Like 389 RAID-5, RAID-6 distributes the syndromes across the drives 390 in one of the available parity distribution methods. 391 392config DM_ZERO 393 tristate "Zero target" 394 depends on BLK_DEV_DM 395 ---help--- 396 A target that discards writes, and returns all zeroes for 397 reads. Useful in some recovery situations. 398 399config DM_MULTIPATH 400 tristate "Multipath target" 401 depends on BLK_DEV_DM 402 # nasty syntax but means make DM_MULTIPATH independent 403 # of SCSI_DH if the latter isn't defined but if 404 # it is, DM_MULTIPATH must depend on it. We get a build 405 # error if SCSI_DH=m and DM_MULTIPATH=y 406 depends on !SCSI_DH || SCSI 407 ---help--- 408 Allow volume managers to support multipath hardware. 409 410config DM_MULTIPATH_QL 411 tristate "I/O Path Selector based on the number of in-flight I/Os" 412 depends on DM_MULTIPATH 413 ---help--- 414 This path selector is a dynamic load balancer which selects 415 the path with the least number of in-flight I/Os. 416 417 If unsure, say N. 418 419config DM_MULTIPATH_ST 420 tristate "I/O Path Selector based on the service time" 421 depends on DM_MULTIPATH 422 ---help--- 423 This path selector is a dynamic load balancer which selects 424 the path expected to complete the incoming I/O in the shortest 425 time. 426 427 If unsure, say N. 428 429config DM_DELAY 430 tristate "I/O delaying target" 431 depends on BLK_DEV_DM 432 ---help--- 433 A target that delays reads and/or writes and can send 434 them to different devices. Useful for testing. 435 436 If unsure, say N. 437 438config DM_UEVENT 439 bool "DM uevents" 440 depends on BLK_DEV_DM 441 ---help--- 442 Generate udev events for DM events. 443 444config DM_FLAKEY 445 tristate "Flakey target" 446 depends on BLK_DEV_DM 447 ---help--- 448 A target that intermittently fails I/O for debugging purposes. 449 450config DM_VERITY 451 tristate "Verity target support" 452 depends on BLK_DEV_DM 453 select CRYPTO 454 select CRYPTO_HASH 455 select DM_BUFIO 456 ---help--- 457 This device-mapper target creates a read-only device that 458 transparently validates the data on one underlying device against 459 a pre-generated tree of cryptographic checksums stored on a second 460 device. 461 462 You'll need to activate the digests you're going to use in the 463 cryptoapi configuration. 464 465 To compile this code as a module, choose M here: the module will 466 be called dm-verity. 467 468 If unsure, say N. 469 470config DM_VERITY_FEC 471 bool "Verity forward error correction support" 472 depends on DM_VERITY 473 select REED_SOLOMON 474 select REED_SOLOMON_DEC8 475 ---help--- 476 Add forward error correction support to dm-verity. This option 477 makes it possible to use pre-generated error correction data to 478 recover from corrupted blocks. 479 480 If unsure, say N. 481 482config DM_SWITCH 483 tristate "Switch target support (EXPERIMENTAL)" 484 depends on BLK_DEV_DM 485 ---help--- 486 This device-mapper target creates a device that supports an arbitrary 487 mapping of fixed-size regions of I/O across a fixed set of paths. 488 The path used for any specific region can be switched dynamically 489 by sending the target a message. 490 491 To compile this code as a module, choose M here: the module will 492 be called dm-switch. 493 494 If unsure, say N. 495 496config DM_LOG_WRITES 497 tristate "Log writes target support" 498 depends on BLK_DEV_DM 499 ---help--- 500 This device-mapper target takes two devices, one device to use 501 normally, one to log all write operations done to the first device. 502 This is for use by file system developers wishing to verify that 503 their fs is writing a consistent file system at all times by allowing 504 them to replay the log in a variety of ways and to check the 505 contents. 506 507 To compile this code as a module, choose M here: the module will 508 be called dm-log-writes. 509 510 If unsure, say N. 511 512endif # MD 513