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 https://www.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 select DAX 204 ---help--- 205 Device-mapper is a low level volume manager. It works by allowing 206 people to specify mappings for ranges of logical sectors. Various 207 mapping types are available, in addition people may write their own 208 modules containing custom mappings if they wish. 209 210 Higher level volume managers such as LVM2 use this driver. 211 212 To compile this as a module, choose M here: the module will be 213 called dm-mod. 214 215 If unsure, say N. 216 217config DM_MQ_DEFAULT 218 bool "request-based DM: use blk-mq I/O path by default" 219 depends on BLK_DEV_DM 220 ---help--- 221 This option enables the blk-mq based I/O path for request-based 222 DM devices by default. With the option the dm_mod.use_blk_mq 223 module/boot option defaults to Y, without it to N, but it can 224 still be overriden either way. 225 226 If unsure say N. 227 228config DM_DEBUG 229 bool "Device mapper debugging support" 230 depends on BLK_DEV_DM 231 ---help--- 232 Enable this for messages that may help debug device-mapper problems. 233 234 If unsure, say N. 235 236config DM_BUFIO 237 tristate 238 depends on BLK_DEV_DM 239 ---help--- 240 This interface allows you to do buffered I/O on a device and acts 241 as a cache, holding recently-read blocks in memory and performing 242 delayed writes. 243 244config DM_DEBUG_BLOCK_MANAGER_LOCKING 245 bool "Block manager locking" 246 depends on DM_BUFIO 247 ---help--- 248 Block manager locking can catch various metadata corruption issues. 249 250 If unsure, say N. 251 252config DM_DEBUG_BLOCK_STACK_TRACING 253 bool "Keep stack trace of persistent data block lock holders" 254 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING 255 select STACKTRACE 256 ---help--- 257 Enable this for messages that may help debug problems with the 258 block manager locking used by thin provisioning and caching. 259 260 If unsure, say N. 261 262config DM_BIO_PRISON 263 tristate 264 depends on BLK_DEV_DM 265 ---help--- 266 Some bio locking schemes used by other device-mapper targets 267 including thin provisioning. 268 269source "drivers/md/persistent-data/Kconfig" 270 271config DM_CRYPT 272 tristate "Crypt target support" 273 depends on BLK_DEV_DM 274 select CRYPTO 275 select CRYPTO_CBC 276 ---help--- 277 This device-mapper target allows you to create a device that 278 transparently encrypts the data on it. You'll need to activate 279 the ciphers you're going to use in the cryptoapi configuration. 280 281 For further information on dm-crypt and userspace tools see: 282 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt> 283 284 To compile this code as a module, choose M here: the module will 285 be called dm-crypt. 286 287 If unsure, say N. 288 289config DM_SNAPSHOT 290 tristate "Snapshot target" 291 depends on BLK_DEV_DM 292 select DM_BUFIO 293 ---help--- 294 Allow volume managers to take writable snapshots of a device. 295 296config DM_THIN_PROVISIONING 297 tristate "Thin provisioning target" 298 depends on BLK_DEV_DM 299 select DM_PERSISTENT_DATA 300 select DM_BIO_PRISON 301 ---help--- 302 Provides thin provisioning and snapshots that share a data store. 303 304config DM_CACHE 305 tristate "Cache target (EXPERIMENTAL)" 306 depends on BLK_DEV_DM 307 default n 308 select DM_PERSISTENT_DATA 309 select DM_BIO_PRISON 310 ---help--- 311 dm-cache attempts to improve performance of a block device by 312 moving frequently used data to a smaller, higher performance 313 device. Different 'policy' plugins can be used to change the 314 algorithms used to select which blocks are promoted, demoted, 315 cleaned etc. It supports writeback and writethrough modes. 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_ERA 330 tristate "Era target (EXPERIMENTAL)" 331 depends on BLK_DEV_DM 332 default n 333 select DM_PERSISTENT_DATA 334 select DM_BIO_PRISON 335 ---help--- 336 dm-era tracks which parts of a block device are written to 337 over time. Useful for maintaining cache coherency when using 338 vendor snapshots. 339 340config DM_MIRROR 341 tristate "Mirror target" 342 depends on BLK_DEV_DM 343 ---help--- 344 Allow volume managers to mirror logical volumes, also 345 needed for live data migration tools such as 'pvmove'. 346 347config DM_LOG_USERSPACE 348 tristate "Mirror userspace logging" 349 depends on DM_MIRROR && NET 350 select CONNECTOR 351 ---help--- 352 The userspace logging module provides a mechanism for 353 relaying the dm-dirty-log API to userspace. Log designs 354 which are more suited to userspace implementation (e.g. 355 shared storage logs) or experimental logs can be implemented 356 by leveraging this framework. 357 358config DM_RAID 359 tristate "RAID 1/4/5/6/10 target" 360 depends on BLK_DEV_DM 361 select MD_RAID0 362 select MD_RAID1 363 select MD_RAID10 364 select MD_RAID456 365 select BLK_DEV_MD 366 ---help--- 367 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings 368 369 A RAID-5 set of N drives with a capacity of C MB per drive provides 370 the capacity of C * (N - 1) MB, and protects against a failure 371 of a single drive. For a given sector (row) number, (N - 1) drives 372 contain data sectors, and one drive contains the parity protection. 373 For a RAID-4 set, the parity blocks are present on a single drive, 374 while a RAID-5 set distributes the parity across the drives in one 375 of the available parity distribution methods. 376 377 A RAID-6 set of N drives with a capacity of C MB per drive 378 provides the capacity of C * (N - 2) MB, and protects 379 against a failure of any two drives. For a given sector 380 (row) number, (N - 2) drives contain data sectors, and two 381 drives contains two independent redundancy syndromes. Like 382 RAID-5, RAID-6 distributes the syndromes across the drives 383 in one of the available parity distribution methods. 384 385config DM_ZERO 386 tristate "Zero target" 387 depends on BLK_DEV_DM 388 ---help--- 389 A target that discards writes, and returns all zeroes for 390 reads. Useful in some recovery situations. 391 392config DM_MULTIPATH 393 tristate "Multipath target" 394 depends on BLK_DEV_DM 395 # nasty syntax but means make DM_MULTIPATH independent 396 # of SCSI_DH if the latter isn't defined but if 397 # it is, DM_MULTIPATH must depend on it. We get a build 398 # error if SCSI_DH=m and DM_MULTIPATH=y 399 depends on !SCSI_DH || SCSI 400 ---help--- 401 Allow volume managers to support multipath hardware. 402 403config DM_MULTIPATH_QL 404 tristate "I/O Path Selector based on the number of in-flight I/Os" 405 depends on DM_MULTIPATH 406 ---help--- 407 This path selector is a dynamic load balancer which selects 408 the path with the least number of in-flight I/Os. 409 410 If unsure, say N. 411 412config DM_MULTIPATH_ST 413 tristate "I/O Path Selector based on the service time" 414 depends on DM_MULTIPATH 415 ---help--- 416 This path selector is a dynamic load balancer which selects 417 the path expected to complete the incoming I/O in the shortest 418 time. 419 420 If unsure, say N. 421 422config DM_DELAY 423 tristate "I/O delaying target" 424 depends on BLK_DEV_DM 425 ---help--- 426 A target that delays reads and/or writes and can send 427 them to different devices. Useful for testing. 428 429 If unsure, say N. 430 431config DM_UEVENT 432 bool "DM uevents" 433 depends on BLK_DEV_DM 434 ---help--- 435 Generate udev events for DM events. 436 437config DM_FLAKEY 438 tristate "Flakey target" 439 depends on BLK_DEV_DM 440 ---help--- 441 A target that intermittently fails I/O for debugging purposes. 442 443config DM_VERITY 444 tristate "Verity target support" 445 depends on BLK_DEV_DM 446 select CRYPTO 447 select CRYPTO_HASH 448 select DM_BUFIO 449 ---help--- 450 This device-mapper target creates a read-only device that 451 transparently validates the data on one underlying device against 452 a pre-generated tree of cryptographic checksums stored on a second 453 device. 454 455 You'll need to activate the digests you're going to use in the 456 cryptoapi configuration. 457 458 To compile this code as a module, choose M here: the module will 459 be called dm-verity. 460 461 If unsure, say N. 462 463config DM_VERITY_FEC 464 bool "Verity forward error correction support" 465 depends on DM_VERITY 466 select REED_SOLOMON 467 select REED_SOLOMON_DEC8 468 ---help--- 469 Add forward error correction support to dm-verity. This option 470 makes it possible to use pre-generated error correction data to 471 recover from corrupted blocks. 472 473 If unsure, say N. 474 475config DM_SWITCH 476 tristate "Switch target support (EXPERIMENTAL)" 477 depends on BLK_DEV_DM 478 ---help--- 479 This device-mapper target creates a device that supports an arbitrary 480 mapping of fixed-size regions of I/O across a fixed set of paths. 481 The path used for any specific region can be switched dynamically 482 by sending the target a message. 483 484 To compile this code as a module, choose M here: the module will 485 be called dm-switch. 486 487 If unsure, say N. 488 489config DM_LOG_WRITES 490 tristate "Log writes target support" 491 depends on BLK_DEV_DM 492 ---help--- 493 This device-mapper target takes two devices, one device to use 494 normally, one to log all write operations done to the first device. 495 This is for use by file system developers wishing to verify that 496 their fs is writing a consistent file system at all times by allowing 497 them to replay the log in a variety of ways and to check the 498 contents. 499 500 To compile this code as a module, choose M here: the module will 501 be called dm-log-writes. 502 503 If unsure, say N. 504 505config DM_INTEGRITY 506 tristate "Integrity target support" 507 depends on BLK_DEV_DM 508 select BLK_DEV_INTEGRITY 509 select DM_BUFIO 510 select CRYPTO 511 select ASYNC_XOR 512 ---help--- 513 This device-mapper target emulates a block device that has 514 additional per-sector tags that can be used for storing 515 integrity information. 516 517 This integrity target is used with the dm-crypt target to 518 provide authenticated disk encryption or it can be used 519 standalone. 520 521 To compile this code as a module, choose M here: the module will 522 be called dm-integrity. 523 524config DM_ZONED 525 tristate "Drive-managed zoned block device target support" 526 depends on BLK_DEV_DM 527 depends on BLK_DEV_ZONED 528 ---help--- 529 This device-mapper target takes a host-managed or host-aware zoned 530 block device and exposes most of its capacity as a regular block 531 device (drive-managed zoned block device) without any write 532 constraints. This is mainly intended for use with file systems that 533 do not natively support zoned block devices but still want to 534 benefit from the increased capacity offered by SMR disks. Other uses 535 by applications using raw block devices (for example object stores) 536 are also possible. 537 538 To compile this code as a module, choose M here: the module will 539 be called dm-zoned. 540 541 If unsure, say N. 542 543endif # MD 544