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" 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. Currently, it can work with raid1 and raid10 192 (limited support). 193 194 If unsure, say N. 195 196source "drivers/md/bcache/Kconfig" 197 198config BLK_DEV_DM_BUILTIN 199 bool 200 201config BLK_DEV_DM 202 tristate "Device mapper support" 203 select BLK_DEV_DM_BUILTIN 204 depends on DAX || DAX=n 205 ---help--- 206 Device-mapper is a low level volume manager. It works by allowing 207 people to specify mappings for ranges of logical sectors. Various 208 mapping types are available, in addition people may write their own 209 modules containing custom mappings if they wish. 210 211 Higher level volume managers such as LVM2 use this driver. 212 213 To compile this as a module, choose M here: the module will be 214 called dm-mod. 215 216 If unsure, say N. 217 218config DM_DEBUG 219 bool "Device mapper debugging support" 220 depends on BLK_DEV_DM 221 ---help--- 222 Enable this for messages that may help debug device-mapper problems. 223 224 If unsure, say N. 225 226config DM_BUFIO 227 tristate 228 depends on BLK_DEV_DM 229 ---help--- 230 This interface allows you to do buffered I/O on a device and acts 231 as a cache, holding recently-read blocks in memory and performing 232 delayed writes. 233 234config DM_DEBUG_BLOCK_MANAGER_LOCKING 235 bool "Block manager locking" 236 depends on DM_BUFIO 237 ---help--- 238 Block manager locking can catch various metadata corruption issues. 239 240 If unsure, say N. 241 242config DM_DEBUG_BLOCK_STACK_TRACING 243 bool "Keep stack trace of persistent data block lock holders" 244 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING 245 select STACKTRACE 246 ---help--- 247 Enable this for messages that may help debug problems with the 248 block manager locking used by thin provisioning and caching. 249 250 If unsure, say N. 251 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_UNSTRIPED 262 tristate "Unstriped target" 263 depends on BLK_DEV_DM 264 ---help--- 265 Unstripes I/O so it is issued solely on a single drive in a HW 266 RAID0 or dm-striped target. 267 268config DM_CRYPT 269 tristate "Crypt target support" 270 depends on BLK_DEV_DM 271 select CRYPTO 272 select CRYPTO_CBC 273 ---help--- 274 This device-mapper target allows you to create a device that 275 transparently encrypts the data on it. You'll need to activate 276 the ciphers you're going to use in the cryptoapi configuration. 277 278 For further information on dm-crypt and userspace tools see: 279 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt> 280 281 To compile this code as a module, choose M here: the module will 282 be called dm-crypt. 283 284 If unsure, say N. 285 286config DM_SNAPSHOT 287 tristate "Snapshot target" 288 depends on BLK_DEV_DM 289 select DM_BUFIO 290 ---help--- 291 Allow volume managers to take writable snapshots of a device. 292 293config DM_THIN_PROVISIONING 294 tristate "Thin provisioning target" 295 depends on BLK_DEV_DM 296 select DM_PERSISTENT_DATA 297 select DM_BIO_PRISON 298 ---help--- 299 Provides thin provisioning and snapshots that share a data store. 300 301config DM_CACHE 302 tristate "Cache target (EXPERIMENTAL)" 303 depends on BLK_DEV_DM 304 default n 305 select DM_PERSISTENT_DATA 306 select DM_BIO_PRISON 307 ---help--- 308 dm-cache attempts to improve performance of a block device by 309 moving frequently used data to a smaller, higher performance 310 device. Different 'policy' plugins can be used to change the 311 algorithms used to select which blocks are promoted, demoted, 312 cleaned etc. It supports writeback and writethrough modes. 313 314config DM_CACHE_SMQ 315 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)" 316 depends on DM_CACHE 317 default y 318 ---help--- 319 A cache policy that uses a multiqueue ordered by recent hits 320 to select which blocks should be promoted and demoted. 321 This is meant to be a general purpose policy. It prioritises 322 reads over writes. This SMQ policy (vs MQ) offers the promise 323 of less memory utilization, improved performance and increased 324 adaptability in the face of changing workloads. 325 326config DM_WRITECACHE 327 tristate "Writecache target" 328 depends on BLK_DEV_DM 329 ---help--- 330 The writecache target caches writes on persistent memory or SSD. 331 It is intended for databases or other programs that need extremely 332 low commit latency. 333 334 The writecache target doesn't cache reads because reads are supposed 335 to be cached in standard RAM. 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_RAID0 370 select MD_RAID1 371 select MD_RAID10 372 select MD_RAID456 373 select BLK_DEV_MD 374 ---help--- 375 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings 376 377 A RAID-5 set of N drives with a capacity of C MB per drive provides 378 the capacity of C * (N - 1) MB, and protects against a failure 379 of a single drive. For a given sector (row) number, (N - 1) drives 380 contain data sectors, and one drive contains the parity protection. 381 For a RAID-4 set, the parity blocks are present on a single drive, 382 while a RAID-5 set distributes the parity across the drives in one 383 of the available parity distribution methods. 384 385 A RAID-6 set of N drives with a capacity of C MB per drive 386 provides the capacity of C * (N - 2) MB, and protects 387 against a failure of any two drives. For a given sector 388 (row) number, (N - 2) drives contain data sectors, and two 389 drives contains two independent redundancy syndromes. Like 390 RAID-5, RAID-6 distributes the syndromes across the drives 391 in one of the available parity distribution methods. 392 393config DM_ZERO 394 tristate "Zero target" 395 depends on BLK_DEV_DM 396 ---help--- 397 A target that discards writes, and returns all zeroes for 398 reads. Useful in some recovery situations. 399 400config DM_MULTIPATH 401 tristate "Multipath target" 402 depends on BLK_DEV_DM 403 # nasty syntax but means make DM_MULTIPATH independent 404 # of SCSI_DH if the latter isn't defined but if 405 # it is, DM_MULTIPATH must depend on it. We get a build 406 # error if SCSI_DH=m and DM_MULTIPATH=y 407 depends on !SCSI_DH || SCSI 408 ---help--- 409 Allow volume managers to support multipath hardware. 410 411config DM_MULTIPATH_QL 412 tristate "I/O Path Selector based on the number of in-flight I/Os" 413 depends on DM_MULTIPATH 414 ---help--- 415 This path selector is a dynamic load balancer which selects 416 the path with the least number of in-flight I/Os. 417 418 If unsure, say N. 419 420config DM_MULTIPATH_ST 421 tristate "I/O Path Selector based on the service time" 422 depends on DM_MULTIPATH 423 ---help--- 424 This path selector is a dynamic load balancer which selects 425 the path expected to complete the incoming I/O in the shortest 426 time. 427 428 If unsure, say N. 429 430config DM_DELAY 431 tristate "I/O delaying target" 432 depends on BLK_DEV_DM 433 ---help--- 434 A target that delays reads and/or writes and can send 435 them to different devices. Useful for testing. 436 437 If unsure, say N. 438 439config DM_INIT 440 bool "DM \"dm-mod.create=\" parameter support" 441 depends on BLK_DEV_DM=y 442 ---help--- 443 Enable "dm-mod.create=" parameter to create mapped devices at init time. 444 This option is useful to allow mounting rootfs without requiring an 445 initramfs. 446 See Documentation/device-mapper/dm-init.txt for dm-mod.create="..." 447 format. 448 449 If unsure, say N. 450 451config DM_UEVENT 452 bool "DM uevents" 453 depends on BLK_DEV_DM 454 ---help--- 455 Generate udev events for DM events. 456 457config DM_FLAKEY 458 tristate "Flakey target" 459 depends on BLK_DEV_DM 460 ---help--- 461 A target that intermittently fails I/O for debugging purposes. 462 463config DM_VERITY 464 tristate "Verity target support" 465 depends on BLK_DEV_DM 466 select CRYPTO 467 select CRYPTO_HASH 468 select DM_BUFIO 469 ---help--- 470 This device-mapper target creates a read-only device that 471 transparently validates the data on one underlying device against 472 a pre-generated tree of cryptographic checksums stored on a second 473 device. 474 475 You'll need to activate the digests you're going to use in the 476 cryptoapi configuration. 477 478 To compile this code as a module, choose M here: the module will 479 be called dm-verity. 480 481 If unsure, say N. 482 483config DM_VERITY_FEC 484 bool "Verity forward error correction support" 485 depends on DM_VERITY 486 select REED_SOLOMON 487 select REED_SOLOMON_DEC8 488 ---help--- 489 Add forward error correction support to dm-verity. This option 490 makes it possible to use pre-generated error correction data to 491 recover from corrupted blocks. 492 493 If unsure, say N. 494 495config DM_SWITCH 496 tristate "Switch target support (EXPERIMENTAL)" 497 depends on BLK_DEV_DM 498 ---help--- 499 This device-mapper target creates a device that supports an arbitrary 500 mapping of fixed-size regions of I/O across a fixed set of paths. 501 The path used for any specific region can be switched dynamically 502 by sending the target a message. 503 504 To compile this code as a module, choose M here: the module will 505 be called dm-switch. 506 507 If unsure, say N. 508 509config DM_LOG_WRITES 510 tristate "Log writes target support" 511 depends on BLK_DEV_DM 512 ---help--- 513 This device-mapper target takes two devices, one device to use 514 normally, one to log all write operations done to the first device. 515 This is for use by file system developers wishing to verify that 516 their fs is writing a consistent file system at all times by allowing 517 them to replay the log in a variety of ways and to check the 518 contents. 519 520 To compile this code as a module, choose M here: the module will 521 be called dm-log-writes. 522 523 If unsure, say N. 524 525config DM_INTEGRITY 526 tristate "Integrity target support" 527 depends on BLK_DEV_DM 528 select BLK_DEV_INTEGRITY 529 select DM_BUFIO 530 select CRYPTO 531 select ASYNC_XOR 532 ---help--- 533 This device-mapper target emulates a block device that has 534 additional per-sector tags that can be used for storing 535 integrity information. 536 537 This integrity target is used with the dm-crypt target to 538 provide authenticated disk encryption or it can be used 539 standalone. 540 541 To compile this code as a module, choose M here: the module will 542 be called dm-integrity. 543 544config DM_ZONED 545 tristate "Drive-managed zoned block device target support" 546 depends on BLK_DEV_DM 547 depends on BLK_DEV_ZONED 548 ---help--- 549 This device-mapper target takes a host-managed or host-aware zoned 550 block device and exposes most of its capacity as a regular block 551 device (drive-managed zoned block device) without any write 552 constraints. This is mainly intended for use with file systems that 553 do not natively support zoned block devices but still want to 554 benefit from the increased capacity offered by SMR disks. Other uses 555 by applications using raw block devices (for example object stores) 556 are also possible. 557 558 To compile this code as a module, choose M here: the module will 559 be called dm-zoned. 560 561 If unsure, say N. 562 563endif # MD 564