drivers/md/Kconfig

   1 #
   2 # Block device driver configuration
   3 #
   4
   5 menuconfig 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
  13 if MD
  14
  15 config 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
  34 config 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
  48 config 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
  61 config 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
  81 config 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
 103 config 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
 122 config 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
 159 config 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
 170 config 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
 180 config 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
 196 source "drivers/md/bcache/Kconfig"
 197
 198 config BLK_DEV_DM_BUILTIN
 199         bool
 200
 201 config 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
 218 config 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
 226 config 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
 234 config 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
 242 config 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
 252 config 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
 259 source "drivers/md/persistent-data/Kconfig"
 260
 261 config 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
 268 config 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
 286 config 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
 293 config 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
 301 config 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
 314 config 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
 326 config 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
 337 config 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
 348 config 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
 355 config 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
 366 config 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
 393 config 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
 400 config 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
 411 config 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
 420 config 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
 430 config 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
 439 config 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
 451 config DM_UEVENT
 452         bool "DM uevents"
 453         depends on BLK_DEV_DM
 454         ---help---
 455         Generate udev events for DM events.
 456
 457 config 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
 463 config 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
 483 config 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
 495 config 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
 509 config 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
 525 config 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
 544 config 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
 563 endif # MD