drivers/md/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 #
   3 # Block device driver configuration
   4 #
   5
   6 menuconfig MD
   7         bool "Multiple devices driver support (RAID and LVM)"
   8         depends on BLOCK
   9         select SRCU
  10         help
  11           Support multiple physical spindles through a single logical device.
  12           Required for RAID and logical volume management.
  13
  14 if MD
  15
  16 config BLK_DEV_MD
  17         tristate "RAID support"
  18         ---help---
  19           This driver lets you combine several hard disk partitions into one
  20           logical block device. This can be used to simply append one
  21           partition to another one or to combine several redundant hard disks
  22           into a RAID1/4/5 device so as to provide protection against hard
  23           disk failures. This is called "Software RAID" since the combining of
  24           the partitions is done by the kernel. "Hardware RAID" means that the
  25           combining is done by a dedicated controller; if you have such a
  26           controller, you do not need to say Y here.
  27
  28           More information about Software RAID on Linux is contained in the
  29           Software RAID mini-HOWTO, available from
  30           <http://www.tldp.org/docs.html#howto>. There you will also learn
  31           where to get the supporting user space utilities raidtools.
  32
  33           If unsure, say N.
  34
  35 config MD_AUTODETECT
  36         bool "Autodetect RAID arrays during kernel boot"
  37         depends on BLK_DEV_MD=y
  38         default y
  39         ---help---
  40           If you say Y here, then the kernel will try to autodetect raid
  41           arrays as part of its boot process.
  42
  43           If you don't use raid and say Y, this autodetection can cause
  44           a several-second delay in the boot time due to various
  45           synchronisation steps that are part of this step.
  46
  47           If unsure, say Y.
  48
  49 config MD_LINEAR
  50         tristate "Linear (append) mode"
  51         depends on BLK_DEV_MD
  52         ---help---
  53           If you say Y here, then your multiple devices driver will be able to
  54           use the so-called linear mode, i.e. it will combine the hard disk
  55           partitions by simply appending one to the other.
  56
  57           To compile this as a module, choose M here: the module
  58           will be called linear.
  59
  60           If unsure, say Y.
  61
  62 config MD_RAID0
  63         tristate "RAID-0 (striping) mode"
  64         depends on BLK_DEV_MD
  65         ---help---
  66           If you say Y here, then your multiple devices driver will be able to
  67           use the so-called raid0 mode, i.e. it will combine the hard disk
  68           partitions into one logical device in such a fashion as to fill them
  69           up evenly, one chunk here and one chunk there. This will increase
  70           the throughput rate if the partitions reside on distinct disks.
  71
  72           Information about Software RAID on Linux is contained in the
  73           Software-RAID mini-HOWTO, available from
  74           <http://www.tldp.org/docs.html#howto>. There you will also
  75           learn where to get the supporting user space utilities raidtools.
  76
  77           To compile this as a module, choose M here: the module
  78           will be called raid0.
  79
  80           If unsure, say Y.
  81
  82 config MD_RAID1
  83         tristate "RAID-1 (mirroring) mode"
  84         depends on BLK_DEV_MD
  85         ---help---
  86           A RAID-1 set consists of several disk drives which are exact copies
  87           of each other.  In the event of a mirror failure, the RAID driver
  88           will continue to use the operational mirrors in the set, providing
  89           an error free MD (multiple device) to the higher levels of the
  90           kernel.  In a set with N drives, the available space is the capacity
  91           of a single drive, and the set protects against a failure of (N - 1)
  92           drives.
  93
  94           Information about Software RAID on Linux is contained in the
  95           Software-RAID mini-HOWTO, available from
  96           <http://www.tldp.org/docs.html#howto>.  There you will also
  97           learn where to get the supporting user space utilities raidtools.
  98
  99           If you want to use such a RAID-1 set, say Y.  To compile this code
 100           as a module, choose M here: the module will be called raid1.
 101
 102           If unsure, say Y.
 103
 104 config MD_RAID10
 105         tristate "RAID-10 (mirrored striping) mode"
 106         depends on BLK_DEV_MD
 107         ---help---
 108           RAID-10 provides a combination of striping (RAID-0) and
 109           mirroring (RAID-1) with easier configuration and more flexible
 110           layout.
 111           Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
 112           be the same size (or at least, only as much as the smallest device
 113           will be used).
 114           RAID-10 provides a variety of layouts that provide different levels
 115           of redundancy and performance.
 116
 117           RAID-10 requires mdadm-1.7.0 or later, available at:
 118
 119           https://www.kernel.org/pub/linux/utils/raid/mdadm/
 120
 121           If unsure, say Y.
 122
 123 config MD_RAID456
 124         tristate "RAID-4/RAID-5/RAID-6 mode"
 125         depends on BLK_DEV_MD
 126         select RAID6_PQ
 127         select LIBCRC32C
 128         select ASYNC_MEMCPY
 129         select ASYNC_XOR
 130         select ASYNC_PQ
 131         select ASYNC_RAID6_RECOV
 132         ---help---
 133           A RAID-5 set of N drives with a capacity of C MB per drive provides
 134           the capacity of C * (N - 1) MB, and protects against a failure
 135           of a single drive. For a given sector (row) number, (N - 1) drives
 136           contain data sectors, and one drive contains the parity protection.
 137           For a RAID-4 set, the parity blocks are present on a single drive,
 138           while a RAID-5 set distributes the parity across the drives in one
 139           of the available parity distribution methods.
 140
 141           A RAID-6 set of N drives with a capacity of C MB per drive
 142           provides the capacity of C * (N - 2) MB, and protects
 143           against a failure of any two drives. For a given sector
 144           (row) number, (N - 2) drives contain data sectors, and two
 145           drives contains two independent redundancy syndromes.  Like
 146           RAID-5, RAID-6 distributes the syndromes across the drives
 147           in one of the available parity distribution methods.
 148
 149           Information about Software RAID on Linux is contained in the
 150           Software-RAID mini-HOWTO, available from
 151           <http://www.tldp.org/docs.html#howto>. There you will also
 152           learn where to get the supporting user space utilities raidtools.
 153
 154           If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y.  To
 155           compile this code as a module, choose M here: the module
 156           will be called raid456.
 157
 158           If unsure, say Y.
 159
 160 config MD_MULTIPATH
 161         tristate "Multipath I/O support"
 162         depends on BLK_DEV_MD
 163         help
 164           MD_MULTIPATH provides a simple multi-path personality for use
 165           the MD framework.  It is not under active development.  New
 166           projects should consider using DM_MULTIPATH which has more
 167           features and more testing.
 168
 169           If unsure, say N.
 170
 171 config MD_FAULTY
 172         tristate "Faulty test module for MD"
 173         depends on BLK_DEV_MD
 174         help
 175           The "faulty" module allows for a block device that occasionally returns
 176           read or write errors.  It is useful for testing.
 177
 178           In unsure, say N.
 179
 180
 181 config MD_CLUSTER
 182         tristate "Cluster Support for MD"
 183         depends on BLK_DEV_MD
 184         depends on DLM
 185         default n
 186         ---help---
 187         Clustering support for MD devices. This enables locking and
 188         synchronization across multiple systems on the cluster, so all
 189         nodes in the cluster can access the MD devices simultaneously.
 190
 191         This brings the redundancy (and uptime) of RAID levels across the
 192         nodes of the cluster. Currently, it can work with raid1 and raid10
 193         (limited support).
 194
 195         If unsure, say N.
 196
 197 source "drivers/md/bcache/Kconfig"
 198
 199 config BLK_DEV_DM_BUILTIN
 200         bool
 201
 202 config BLK_DEV_DM
 203         tristate "Device mapper support"
 204         select BLK_DEV_DM_BUILTIN
 205         depends on DAX || DAX=n
 206         ---help---
 207           Device-mapper is a low level volume manager.  It works by allowing
 208           people to specify mappings for ranges of logical sectors.  Various
 209           mapping types are available, in addition people may write their own
 210           modules containing custom mappings if they wish.
 211
 212           Higher level volume managers such as LVM2 use this driver.
 213
 214           To compile this as a module, choose M here: the module will be
 215           called dm-mod.
 216
 217           If unsure, say N.
 218
 219 config DM_DEBUG
 220         bool "Device mapper debugging support"
 221         depends on BLK_DEV_DM
 222         ---help---
 223           Enable this for messages that may help debug device-mapper problems.
 224
 225           If unsure, say N.
 226
 227 config DM_BUFIO
 228        tristate
 229        depends on BLK_DEV_DM
 230        ---help---
 231          This interface allows you to do buffered I/O on a device and acts
 232          as a cache, holding recently-read blocks in memory and performing
 233          delayed writes.
 234
 235 config DM_DEBUG_BLOCK_MANAGER_LOCKING
 236        bool "Block manager locking"
 237        depends on DM_BUFIO
 238        ---help---
 239          Block manager locking can catch various metadata corruption issues.
 240
 241          If unsure, say N.
 242
 243 config DM_DEBUG_BLOCK_STACK_TRACING
 244        bool "Keep stack trace of persistent data block lock holders"
 245        depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
 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.
 252
 253 config DM_BIO_PRISON
 254        tristate
 255        depends on BLK_DEV_DM
 256        ---help---
 257          Some bio locking schemes used by other device-mapper targets
 258          including thin provisioning.
 259
 260 source "drivers/md/persistent-data/Kconfig"
 261
 262 config DM_UNSTRIPED
 263        tristate "Unstriped target"
 264        depends on BLK_DEV_DM
 265        ---help---
 266           Unstripes I/O so it is issued solely on a single drive in a HW
 267           RAID0 or dm-striped target.
 268
 269 config DM_CRYPT
 270         tristate "Crypt target support"
 271         depends on BLK_DEV_DM
 272         select CRYPTO
 273         select CRYPTO_CBC
 274         ---help---
 275           This device-mapper target allows you to create a device that
 276           transparently encrypts the data on it. You'll need to activate
 277           the ciphers you're going to use in the cryptoapi configuration.
 278
 279           For further information on dm-crypt and userspace tools see:
 280           <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
 281
 282           To compile this code as a module, choose M here: the module will
 283           be called dm-crypt.
 284
 285           If unsure, say N.
 286
 287 config DM_SNAPSHOT
 288        tristate "Snapshot target"
 289        depends on BLK_DEV_DM
 290        select DM_BUFIO
 291        ---help---
 292          Allow volume managers to take writable snapshots of a device.
 293
 294 config DM_THIN_PROVISIONING
 295        tristate "Thin provisioning target"
 296        depends on BLK_DEV_DM
 297        select DM_PERSISTENT_DATA
 298        select DM_BIO_PRISON
 299        ---help---
 300          Provides thin provisioning and snapshots that share a data store.
 301
 302 config DM_CACHE
 303        tristate "Cache target (EXPERIMENTAL)"
 304        depends on BLK_DEV_DM
 305        default n
 306        select DM_PERSISTENT_DATA
 307        select DM_BIO_PRISON
 308        ---help---
 309          dm-cache attempts to improve performance of a block device by
 310          moving frequently used data to a smaller, higher performance
 311          device.  Different 'policy' plugins can be used to change the
 312          algorithms used to select which blocks are promoted, demoted,
 313          cleaned etc.  It supports writeback and writethrough modes.
 314
 315 config DM_CACHE_SMQ
 316        tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
 317        depends on DM_CACHE
 318        default y
 319        ---help---
 320          A cache policy that uses a multiqueue ordered by recent hits
 321          to select which blocks should be promoted and demoted.
 322          This is meant to be a general purpose policy.  It prioritises
 323          reads over writes.  This SMQ policy (vs MQ) offers the promise
 324          of less memory utilization, improved performance and increased
 325          adaptability in the face of changing workloads.
 326
 327 config DM_WRITECACHE
 328         tristate "Writecache target"
 329         depends on BLK_DEV_DM
 330         ---help---
 331            The writecache target caches writes on persistent memory or SSD.
 332            It is intended for databases or other programs that need extremely
 333            low commit latency.
 334
 335            The writecache target doesn't cache reads because reads are supposed
 336            to be cached in standard RAM.
 337
 338 config DM_ERA
 339        tristate "Era target (EXPERIMENTAL)"
 340        depends on BLK_DEV_DM
 341        default n
 342        select DM_PERSISTENT_DATA
 343        select DM_BIO_PRISON
 344        ---help---
 345          dm-era tracks which parts of a block device are written to
 346          over time.  Useful for maintaining cache coherency when using
 347          vendor snapshots.
 348
 349 config DM_MIRROR
 350        tristate "Mirror target"
 351        depends on BLK_DEV_DM
 352        ---help---
 353          Allow volume managers to mirror logical volumes, also
 354          needed for live data migration tools such as 'pvmove'.
 355
 356 config DM_LOG_USERSPACE
 357         tristate "Mirror userspace logging"
 358         depends on DM_MIRROR && NET
 359         select CONNECTOR
 360         ---help---
 361           The userspace logging module provides a mechanism for
 362           relaying the dm-dirty-log API to userspace.  Log designs
 363           which are more suited to userspace implementation (e.g.
 364           shared storage logs) or experimental logs can be implemented
 365           by leveraging this framework.
 366
 367 config DM_RAID
 368        tristate "RAID 1/4/5/6/10 target"
 369        depends on BLK_DEV_DM
 370        select MD_RAID0
 371        select MD_RAID1
 372        select MD_RAID10
 373        select MD_RAID456
 374        select BLK_DEV_MD
 375        ---help---
 376          A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
 377
 378          A RAID-5 set of N drives with a capacity of C MB per drive provides
 379          the capacity of C * (N - 1) MB, and protects against a failure
 380          of a single drive. For a given sector (row) number, (N - 1) drives
 381          contain data sectors, and one drive contains the parity protection.
 382          For a RAID-4 set, the parity blocks are present on a single drive,
 383          while a RAID-5 set distributes the parity across the drives in one
 384          of the available parity distribution methods.
 385
 386          A RAID-6 set of N drives with a capacity of C MB per drive
 387          provides the capacity of C * (N - 2) MB, and protects
 388          against a failure of any two drives. For a given sector
 389          (row) number, (N - 2) drives contain data sectors, and two
 390          drives contains two independent redundancy syndromes.  Like
 391          RAID-5, RAID-6 distributes the syndromes across the drives
 392          in one of the available parity distribution methods.
 393
 394 config DM_ZERO
 395         tristate "Zero target"
 396         depends on BLK_DEV_DM
 397         ---help---
 398           A target that discards writes, and returns all zeroes for
 399           reads.  Useful in some recovery situations.
 400
 401 config DM_MULTIPATH
 402         tristate "Multipath target"
 403         depends on BLK_DEV_DM
 404         # nasty syntax but means make DM_MULTIPATH independent
 405         # of SCSI_DH if the latter isn't defined but if
 406         # it is, DM_MULTIPATH must depend on it.  We get a build
 407         # error if SCSI_DH=m and DM_MULTIPATH=y
 408         depends on !SCSI_DH || SCSI
 409         ---help---
 410           Allow volume managers to support multipath hardware.
 411
 412 config DM_MULTIPATH_QL
 413         tristate "I/O Path Selector based on the number of in-flight I/Os"
 414         depends on DM_MULTIPATH
 415         ---help---
 416           This path selector is a dynamic load balancer which selects
 417           the path with the least number of in-flight I/Os.
 418
 419           If unsure, say N.
 420
 421 config DM_MULTIPATH_ST
 422         tristate "I/O Path Selector based on the service time"
 423         depends on DM_MULTIPATH
 424         ---help---
 425           This path selector is a dynamic load balancer which selects
 426           the path expected to complete the incoming I/O in the shortest
 427           time.
 428
 429           If unsure, say N.
 430
 431 config DM_DELAY
 432         tristate "I/O delaying target"
 433         depends on BLK_DEV_DM
 434         ---help---
 435         A target that delays reads and/or writes and can send
 436         them to different devices.  Useful for testing.
 437
 438         If unsure, say N.
 439
 440 config DM_DUST
 441         tristate "Bad sector simulation target"
 442         depends on BLK_DEV_DM
 443         ---help---
 444         A target that simulates bad sector behavior.
 445         Useful for testing.
 446
 447         If unsure, say N.
 448
 449 config DM_INIT
 450         bool "DM \"dm-mod.create=\" parameter support"
 451         depends on BLK_DEV_DM=y
 452         ---help---
 453         Enable "dm-mod.create=" parameter to create mapped devices at init time.
 454         This option is useful to allow mounting rootfs without requiring an
 455         initramfs.
 456         See Documentation/device-mapper/dm-init.txt for dm-mod.create="..."
 457         format.
 458
 459         If unsure, say N.
 460
 461 config DM_UEVENT
 462         bool "DM uevents"
 463         depends on BLK_DEV_DM
 464         ---help---
 465         Generate udev events for DM events.
 466
 467 config DM_FLAKEY
 468        tristate "Flakey target"
 469        depends on BLK_DEV_DM
 470        ---help---
 471          A target that intermittently fails I/O for debugging purposes.
 472
 473 config DM_VERITY
 474         tristate "Verity target support"
 475         depends on BLK_DEV_DM
 476         select CRYPTO
 477         select CRYPTO_HASH
 478         select DM_BUFIO
 479         ---help---
 480           This device-mapper target creates a read-only device that
 481           transparently validates the data on one underlying device against
 482           a pre-generated tree of cryptographic checksums stored on a second
 483           device.
 484
 485           You'll need to activate the digests you're going to use in the
 486           cryptoapi configuration.
 487
 488           To compile this code as a module, choose M here: the module will
 489           be called dm-verity.
 490
 491           If unsure, say N.
 492
 493 config DM_VERITY_FEC
 494         bool "Verity forward error correction support"
 495         depends on DM_VERITY
 496         select REED_SOLOMON
 497         select REED_SOLOMON_DEC8
 498         ---help---
 499           Add forward error correction support to dm-verity. This option
 500           makes it possible to use pre-generated error correction data to
 501           recover from corrupted blocks.
 502
 503           If unsure, say N.
 504
 505 config DM_SWITCH
 506         tristate "Switch target support (EXPERIMENTAL)"
 507         depends on BLK_DEV_DM
 508         ---help---
 509           This device-mapper target creates a device that supports an arbitrary
 510           mapping of fixed-size regions of I/O across a fixed set of paths.
 511           The path used for any specific region can be switched dynamically
 512           by sending the target a message.
 513
 514           To compile this code as a module, choose M here: the module will
 515           be called dm-switch.
 516
 517           If unsure, say N.
 518
 519 config DM_LOG_WRITES
 520         tristate "Log writes target support"
 521         depends on BLK_DEV_DM
 522         ---help---
 523           This device-mapper target takes two devices, one device to use
 524           normally, one to log all write operations done to the first device.
 525           This is for use by file system developers wishing to verify that
 526           their fs is writing a consistent file system at all times by allowing
 527           them to replay the log in a variety of ways and to check the
 528           contents.
 529
 530           To compile this code as a module, choose M here: the module will
 531           be called dm-log-writes.
 532
 533           If unsure, say N.
 534
 535 config DM_INTEGRITY
 536         tristate "Integrity target support"
 537         depends on BLK_DEV_DM
 538         select BLK_DEV_INTEGRITY
 539         select DM_BUFIO
 540         select CRYPTO
 541         select ASYNC_XOR
 542         ---help---
 543           This device-mapper target emulates a block device that has
 544           additional per-sector tags that can be used for storing
 545           integrity information.
 546
 547           This integrity target is used with the dm-crypt target to
 548           provide authenticated disk encryption or it can be used
 549           standalone.
 550
 551           To compile this code as a module, choose M here: the module will
 552           be called dm-integrity.
 553
 554 config DM_ZONED
 555         tristate "Drive-managed zoned block device target support"
 556         depends on BLK_DEV_DM
 557         depends on BLK_DEV_ZONED
 558         ---help---
 559           This device-mapper target takes a host-managed or host-aware zoned
 560           block device and exposes most of its capacity as a regular block
 561           device (drive-managed zoned block device) without any write
 562           constraints. This is mainly intended for use with file systems that
 563           do not natively support zoned block devices but still want to
 564           benefit from the increased capacity offered by SMR disks. Other uses
 565           by applications using raw block devices (for example object stores)
 566           are also possible.
 567
 568           To compile this code as a module, choose M here: the module will
 569           be called dm-zoned.
 570
 571           If unsure, say N.
 572
 573 endif # MD