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_DEBUG_BLOCK_STACK_TRACING
 244        bool "Keep stack trace of persistent data block lock holders"
 245        depends on STACKTRACE_SUPPORT && DM_BUFIO
 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 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_CRYPT
 262         tristate "Crypt target support"
 263         depends on BLK_DEV_DM
 264         select CRYPTO
 265         select CRYPTO_CBC
 266         ---help---
 267           This device-mapper target allows you to create a device that
 268           transparently encrypts the data on it. You'll need to activate
 269           the ciphers you're going to use in the cryptoapi configuration.
 270
 271           For further information on dm-crypt and userspace tools see:
 272           <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
 273
 274           To compile this code as a module, choose M here: the module will
 275           be called dm-crypt.
 276
 277           If unsure, say N.
 278
 279 config DM_SNAPSHOT
 280        tristate "Snapshot target"
 281        depends on BLK_DEV_DM
 282        select DM_BUFIO
 283        ---help---
 284          Allow volume managers to take writable snapshots of a device.
 285
 286 config DM_THIN_PROVISIONING
 287        tristate "Thin provisioning target"
 288        depends on BLK_DEV_DM
 289        select DM_PERSISTENT_DATA
 290        select DM_BIO_PRISON
 291        ---help---
 292          Provides thin provisioning and snapshots that share a data store.
 293
 294 config DM_CACHE
 295        tristate "Cache target (EXPERIMENTAL)"
 296        depends on BLK_DEV_DM
 297        default n
 298        select DM_PERSISTENT_DATA
 299        select DM_BIO_PRISON
 300        ---help---
 301          dm-cache attempts to improve performance of a block device by
 302          moving frequently used data to a smaller, higher performance
 303          device.  Different 'policy' plugins can be used to change the
 304          algorithms used to select which blocks are promoted, demoted,
 305          cleaned etc.  It supports writeback and writethrough modes.
 306
 307 config DM_CACHE_MQ
 308        tristate "MQ Cache Policy (EXPERIMENTAL)"
 309        depends on DM_CACHE
 310        default y
 311        ---help---
 312          A cache policy that uses a multiqueue ordered by recent hit
 313          count to select which blocks should be promoted and demoted.
 314          This is meant to be a general purpose policy.  It prioritises
 315          reads over writes.
 316
 317 config 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
 329 config DM_CACHE_CLEANER
 330        tristate "Cleaner Cache Policy (EXPERIMENTAL)"
 331        depends on DM_CACHE
 332        default y
 333        ---help---
 334          A simple cache policy that writes back all data to the
 335          origin.  Used when decommissioning a dm-cache.
 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_RAID1
 370        select MD_RAID10
 371        select MD_RAID456
 372        select BLK_DEV_MD
 373        ---help---
 374          A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
 375
 376          A RAID-5 set of N drives with a capacity of C MB per drive provides
 377          the capacity of C * (N - 1) MB, and protects against a failure
 378          of a single drive. For a given sector (row) number, (N - 1) drives
 379          contain data sectors, and one drive contains the parity protection.
 380          For a RAID-4 set, the parity blocks are present on a single drive,
 381          while a RAID-5 set distributes the parity across the drives in one
 382          of the available parity distribution methods.
 383
 384          A RAID-6 set of N drives with a capacity of C MB per drive
 385          provides the capacity of C * (N - 2) MB, and protects
 386          against a failure of any two drives. For a given sector
 387          (row) number, (N - 2) drives contain data sectors, and two
 388          drives contains two independent redundancy syndromes.  Like
 389          RAID-5, RAID-6 distributes the syndromes across the drives
 390          in one of the available parity distribution methods.
 391
 392 config DM_ZERO
 393         tristate "Zero target"
 394         depends on BLK_DEV_DM
 395         ---help---
 396           A target that discards writes, and returns all zeroes for
 397           reads.  Useful in some recovery situations.
 398
 399 config DM_MULTIPATH
 400         tristate "Multipath target"
 401         depends on BLK_DEV_DM
 402         # nasty syntax but means make DM_MULTIPATH independent
 403         # of SCSI_DH if the latter isn't defined but if
 404         # it is, DM_MULTIPATH must depend on it.  We get a build
 405         # error if SCSI_DH=m and DM_MULTIPATH=y
 406         depends on !SCSI_DH || SCSI
 407         ---help---
 408           Allow volume managers to support multipath hardware.
 409
 410 config DM_MULTIPATH_QL
 411         tristate "I/O Path Selector based on the number of in-flight I/Os"
 412         depends on DM_MULTIPATH
 413         ---help---
 414           This path selector is a dynamic load balancer which selects
 415           the path with the least number of in-flight I/Os.
 416
 417           If unsure, say N.
 418
 419 config DM_MULTIPATH_ST
 420         tristate "I/O Path Selector based on the service time"
 421         depends on DM_MULTIPATH
 422         ---help---
 423           This path selector is a dynamic load balancer which selects
 424           the path expected to complete the incoming I/O in the shortest
 425           time.
 426
 427           If unsure, say N.
 428
 429 config DM_DELAY
 430         tristate "I/O delaying target"
 431         depends on BLK_DEV_DM
 432         ---help---
 433         A target that delays reads and/or writes and can send
 434         them to different devices.  Useful for testing.
 435
 436         If unsure, say N.
 437
 438 config DM_UEVENT
 439         bool "DM uevents"
 440         depends on BLK_DEV_DM
 441         ---help---
 442         Generate udev events for DM events.
 443
 444 config DM_FLAKEY
 445        tristate "Flakey target"
 446        depends on BLK_DEV_DM
 447        ---help---
 448          A target that intermittently fails I/O for debugging purposes.
 449
 450 config DM_VERITY
 451         tristate "Verity target support"
 452         depends on BLK_DEV_DM
 453         select CRYPTO
 454         select CRYPTO_HASH
 455         select DM_BUFIO
 456         ---help---
 457           This device-mapper target creates a read-only device that
 458           transparently validates the data on one underlying device against
 459           a pre-generated tree of cryptographic checksums stored on a second
 460           device.
 461
 462           You'll need to activate the digests you're going to use in the
 463           cryptoapi configuration.
 464
 465           To compile this code as a module, choose M here: the module will
 466           be called dm-verity.
 467
 468           If unsure, say N.
 469
 470 config DM_VERITY_FEC
 471         bool "Verity forward error correction support"
 472         depends on DM_VERITY
 473         select REED_SOLOMON
 474         select REED_SOLOMON_DEC8
 475         ---help---
 476           Add forward error correction support to dm-verity. This option
 477           makes it possible to use pre-generated error correction data to
 478           recover from corrupted blocks.
 479
 480           If unsure, say N.
 481
 482 config DM_SWITCH
 483         tristate "Switch target support (EXPERIMENTAL)"
 484         depends on BLK_DEV_DM
 485         ---help---
 486           This device-mapper target creates a device that supports an arbitrary
 487           mapping of fixed-size regions of I/O across a fixed set of paths.
 488           The path used for any specific region can be switched dynamically
 489           by sending the target a message.
 490
 491           To compile this code as a module, choose M here: the module will
 492           be called dm-switch.
 493
 494           If unsure, say N.
 495
 496 config DM_LOG_WRITES
 497         tristate "Log writes target support"
 498         depends on BLK_DEV_DM
 499         ---help---
 500           This device-mapper target takes two devices, one device to use
 501           normally, one to log all write operations done to the first device.
 502           This is for use by file system developers wishing to verify that
 503           their fs is writing a consistent file system at all times by allowing
 504           them to replay the log in a variety of ways and to check the
 505           contents.
 506
 507           To compile this code as a module, choose M here: the module will
 508           be called dm-log-writes.
 509
 510           If unsure, say N.
 511
 512 endif # MD