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           ftp://ftp.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 (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
 195 source "drivers/md/bcache/Kconfig"
 196
 197 config BLK_DEV_DM_BUILTIN
 198         bool
 199
 200 config 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
 216 config 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
 227 config 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
 235 config 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
 243 config DM_BIO_PRISON
 244        tristate
 245        depends on BLK_DEV_DM
 246        ---help---
 247          Some bio locking schemes used by other device-mapper targets
 248          including thin provisioning.
 249
 250 source "drivers/md/persistent-data/Kconfig"
 251
 252 config DM_CRYPT
 253         tristate "Crypt target support"
 254         depends on BLK_DEV_DM
 255         select CRYPTO
 256         select CRYPTO_CBC
 257         ---help---
 258           This device-mapper target allows you to create a device that
 259           transparently encrypts the data on it. You'll need to activate
 260           the ciphers you're going to use in the cryptoapi configuration.
 261
 262           For further information on dm-crypt and userspace tools see:
 263           <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
 264
 265           To compile this code as a module, choose M here: the module will
 266           be called dm-crypt.
 267
 268           If unsure, say N.
 269
 270 config DM_SNAPSHOT
 271        tristate "Snapshot target"
 272        depends on BLK_DEV_DM
 273        select DM_BUFIO
 274        ---help---
 275          Allow volume managers to take writable snapshots of a device.
 276
 277 config DM_THIN_PROVISIONING
 278        tristate "Thin provisioning target"
 279        depends on BLK_DEV_DM
 280        select DM_PERSISTENT_DATA
 281        select DM_BIO_PRISON
 282        ---help---
 283          Provides thin provisioning and snapshots that share a data store.
 284
 285 config DM_CACHE
 286        tristate "Cache target (EXPERIMENTAL)"
 287        depends on BLK_DEV_DM
 288        default n
 289        select DM_PERSISTENT_DATA
 290        select DM_BIO_PRISON
 291        ---help---
 292          dm-cache attempts to improve performance of a block device by
 293          moving frequently used data to a smaller, higher performance
 294          device.  Different 'policy' plugins can be used to change the
 295          algorithms used to select which blocks are promoted, demoted,
 296          cleaned etc.  It supports writeback and writethrough modes.
 297
 298 config DM_CACHE_MQ
 299        tristate "MQ Cache Policy (EXPERIMENTAL)"
 300        depends on DM_CACHE
 301        default y
 302        ---help---
 303          A cache policy that uses a multiqueue ordered by recent hit
 304          count to select which blocks should be promoted and demoted.
 305          This is meant to be a general purpose policy.  It prioritises
 306          reads over writes.
 307
 308 config DM_CACHE_SMQ
 309        tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
 310        depends on DM_CACHE
 311        default y
 312        ---help---
 313          A cache policy that uses a multiqueue ordered by recent hits
 314          to select which blocks should be promoted and demoted.
 315          This is meant to be a general purpose policy.  It prioritises
 316          reads over writes.  This SMQ policy (vs MQ) offers the promise
 317          of less memory utilization, improved performance and increased
 318          adaptability in the face of changing workloads.
 319
 320 config DM_CACHE_CLEANER
 321        tristate "Cleaner Cache Policy (EXPERIMENTAL)"
 322        depends on DM_CACHE
 323        default y
 324        ---help---
 325          A simple cache policy that writes back all data to the
 326          origin.  Used when decommissioning a dm-cache.
 327
 328 config DM_ERA
 329        tristate "Era target (EXPERIMENTAL)"
 330        depends on BLK_DEV_DM
 331        default n
 332        select DM_PERSISTENT_DATA
 333        select DM_BIO_PRISON
 334        ---help---
 335          dm-era tracks which parts of a block device are written to
 336          over time.  Useful for maintaining cache coherency when using
 337          vendor snapshots.
 338
 339 config DM_MIRROR
 340        tristate "Mirror target"
 341        depends on BLK_DEV_DM
 342        ---help---
 343          Allow volume managers to mirror logical volumes, also
 344          needed for live data migration tools such as 'pvmove'.
 345
 346 config DM_LOG_USERSPACE
 347         tristate "Mirror userspace logging"
 348         depends on DM_MIRROR && NET
 349         select CONNECTOR
 350         ---help---
 351           The userspace logging module provides a mechanism for
 352           relaying the dm-dirty-log API to userspace.  Log designs
 353           which are more suited to userspace implementation (e.g.
 354           shared storage logs) or experimental logs can be implemented
 355           by leveraging this framework.
 356
 357 config DM_RAID
 358        tristate "RAID 1/4/5/6/10 target"
 359        depends on BLK_DEV_DM
 360        select MD_RAID1
 361        select MD_RAID10
 362        select MD_RAID456
 363        select BLK_DEV_MD
 364        ---help---
 365          A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
 366
 367          A RAID-5 set of N drives with a capacity of C MB per drive provides
 368          the capacity of C * (N - 1) MB, and protects against a failure
 369          of a single drive. For a given sector (row) number, (N - 1) drives
 370          contain data sectors, and one drive contains the parity protection.
 371          For a RAID-4 set, the parity blocks are present on a single drive,
 372          while a RAID-5 set distributes the parity across the drives in one
 373          of the available parity distribution methods.
 374
 375          A RAID-6 set of N drives with a capacity of C MB per drive
 376          provides the capacity of C * (N - 2) MB, and protects
 377          against a failure of any two drives. For a given sector
 378          (row) number, (N - 2) drives contain data sectors, and two
 379          drives contains two independent redundancy syndromes.  Like
 380          RAID-5, RAID-6 distributes the syndromes across the drives
 381          in one of the available parity distribution methods.
 382
 383 config DM_ZERO
 384         tristate "Zero target"
 385         depends on BLK_DEV_DM
 386         ---help---
 387           A target that discards writes, and returns all zeroes for
 388           reads.  Useful in some recovery situations.
 389
 390 config DM_MULTIPATH
 391         tristate "Multipath target"
 392         depends on BLK_DEV_DM
 393         # nasty syntax but means make DM_MULTIPATH independent
 394         # of SCSI_DH if the latter isn't defined but if
 395         # it is, DM_MULTIPATH must depend on it.  We get a build
 396         # error if SCSI_DH=m and DM_MULTIPATH=y
 397         depends on !SCSI_DH || SCSI
 398         ---help---
 399           Allow volume managers to support multipath hardware.
 400
 401 config DM_MULTIPATH_QL
 402         tristate "I/O Path Selector based on the number of in-flight I/Os"
 403         depends on DM_MULTIPATH
 404         ---help---
 405           This path selector is a dynamic load balancer which selects
 406           the path with the least number of in-flight I/Os.
 407
 408           If unsure, say N.
 409
 410 config DM_MULTIPATH_ST
 411         tristate "I/O Path Selector based on the service time"
 412         depends on DM_MULTIPATH
 413         ---help---
 414           This path selector is a dynamic load balancer which selects
 415           the path expected to complete the incoming I/O in the shortest
 416           time.
 417
 418           If unsure, say N.
 419
 420 config DM_DELAY
 421         tristate "I/O delaying target"
 422         depends on BLK_DEV_DM
 423         ---help---
 424         A target that delays reads and/or writes and can send
 425         them to different devices.  Useful for testing.
 426
 427         If unsure, say N.
 428
 429 config DM_UEVENT
 430         bool "DM uevents"
 431         depends on BLK_DEV_DM
 432         ---help---
 433         Generate udev events for DM events.
 434
 435 config DM_FLAKEY
 436        tristate "Flakey target"
 437        depends on BLK_DEV_DM
 438        ---help---
 439          A target that intermittently fails I/O for debugging purposes.
 440
 441 config DM_VERITY
 442         tristate "Verity target support"
 443         depends on BLK_DEV_DM
 444         select CRYPTO
 445         select CRYPTO_HASH
 446         select DM_BUFIO
 447         ---help---
 448           This device-mapper target creates a read-only device that
 449           transparently validates the data on one underlying device against
 450           a pre-generated tree of cryptographic checksums stored on a second
 451           device.
 452
 453           You'll need to activate the digests you're going to use in the
 454           cryptoapi configuration.
 455
 456           To compile this code as a module, choose M here: the module will
 457           be called dm-verity.
 458
 459           If unsure, say N.
 460
 461 config DM_VERITY_HASH_PREFETCH_MIN_SIZE_128
 462         bool "Prefetch size 128"
 463
 464 config DM_VERITY_HASH_PREFETCH_MIN_SIZE
 465         int "Verity hash prefetch minimum size"
 466         depends on DM_VERITY
 467         range 1 4096
 468         default 128 if DM_VERITY_HASH_PREFETCH_MIN_SIZE_128
 469         default 1
 470         ---help---
 471           This sets minimum number of hash blocks to prefetch for dm-verity.
 472           For devices like eMMC, having larger prefetch size like 128 can improve
 473           performance with increased memory consumption for keeping more hashes
 474           in RAM.
 475
 476 config DM_VERITY_FEC
 477         bool "Verity forward error correction support"
 478         depends on DM_VERITY
 479         select REED_SOLOMON
 480         select REED_SOLOMON_DEC8
 481         ---help---
 482           Add forward error correction support to dm-verity. This option
 483           makes it possible to use pre-generated error correction data to
 484           recover from corrupted blocks.
 485
 486           If unsure, say N.
 487
 488 config DM_SWITCH
 489         tristate "Switch target support (EXPERIMENTAL)"
 490         depends on BLK_DEV_DM
 491         ---help---
 492           This device-mapper target creates a device that supports an arbitrary
 493           mapping of fixed-size regions of I/O across a fixed set of paths.
 494           The path used for any specific region can be switched dynamically
 495           by sending the target a message.
 496
 497           To compile this code as a module, choose M here: the module will
 498           be called dm-switch.
 499
 500           If unsure, say N.
 501
 502 config DM_LOG_WRITES
 503         tristate "Log writes target support"
 504         depends on BLK_DEV_DM
 505         ---help---
 506           This device-mapper target takes two devices, one device to use
 507           normally, one to log all write operations done to the first device.
 508           This is for use by file system developers wishing to verify that
 509           their fs is writing a consistent file system at all times by allowing
 510           them to replay the log in a variety of ways and to check the
 511           contents.
 512
 513           To compile this code as a module, choose M here: the module will
 514           be called dm-log-writes.
 515
 516           If unsure, say N.
 517
 518 config DM_ANDROID_VERITY
 519         tristate "Android verity target support"
 520         depends on DM_VERITY
 521         depends on X509_CERTIFICATE_PARSER
 522         depends on SYSTEM_TRUSTED_KEYRING
 523         depends on PUBLIC_KEY_ALGO_RSA
 524         depends on KEYS
 525         depends on ASYMMETRIC_KEY_TYPE
 526         depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
 527         depends on MD_LINEAR
 528         select DM_VERITY_HASH_PREFETCH_MIN_SIZE_128
 529         ---help---
 530           This device-mapper target is virtually a VERITY target. This
 531           target is setup by reading the metadata contents piggybacked
 532           to the actual data blocks in the block device. The signature
 533           of the metadata contents are verified against the key included
 534           in the system keyring. Upon success, the underlying verity
 535           target is setup.
 536 endif # MD