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 (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         select DAX
 204         ---help---
 205           Device-mapper is a low level volume manager.  It works by allowing
 206           people to specify mappings for ranges of logical sectors.  Various
 207           mapping types are available, in addition people may write their own
 208           modules containing custom mappings if they wish.
 209
 210           Higher level volume managers such as LVM2 use this driver.
 211
 212           To compile this as a module, choose M here: the module will be
 213           called dm-mod.
 214
 215           If unsure, say N.
 216
 217 config DM_MQ_DEFAULT
 218         bool "request-based DM: use blk-mq I/O path by default"
 219         depends on BLK_DEV_DM
 220         ---help---
 221           This option enables the blk-mq based I/O path for request-based
 222           DM devices by default.  With the option the dm_mod.use_blk_mq
 223           module/boot option defaults to Y, without it to N, but it can
 224           still be overriden either way.
 225
 226           If unsure say N.
 227
 228 config DM_DEBUG
 229         bool "Device mapper debugging support"
 230         depends on BLK_DEV_DM
 231         ---help---
 232           Enable this for messages that may help debug device-mapper problems.
 233
 234           If unsure, say N.
 235
 236 config DM_BUFIO
 237        tristate
 238        depends on BLK_DEV_DM
 239        ---help---
 240          This interface allows you to do buffered I/O on a device and acts
 241          as a cache, holding recently-read blocks in memory and performing
 242          delayed writes.
 243
 244 config DM_DEBUG_BLOCK_MANAGER_LOCKING
 245        bool "Block manager locking"
 246        depends on DM_BUFIO
 247        ---help---
 248          Block manager locking can catch various metadata corruption issues.
 249
 250          If unsure, say N.
 251
 252 config DM_DEBUG_BLOCK_STACK_TRACING
 253        bool "Keep stack trace of persistent data block lock holders"
 254        depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
 255        select STACKTRACE
 256        ---help---
 257          Enable this for messages that may help debug problems with the
 258          block manager locking used by thin provisioning and caching.
 259
 260          If unsure, say N.
 261
 262 config DM_BIO_PRISON
 263        tristate
 264        depends on BLK_DEV_DM
 265        ---help---
 266          Some bio locking schemes used by other device-mapper targets
 267          including thin provisioning.
 268
 269 source "drivers/md/persistent-data/Kconfig"
 270
 271 config DM_CRYPT
 272         tristate "Crypt target support"
 273         depends on BLK_DEV_DM
 274         select CRYPTO
 275         select CRYPTO_CBC
 276         ---help---
 277           This device-mapper target allows you to create a device that
 278           transparently encrypts the data on it. You'll need to activate
 279           the ciphers you're going to use in the cryptoapi configuration.
 280
 281           For further information on dm-crypt and userspace tools see:
 282           <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
 283
 284           To compile this code as a module, choose M here: the module will
 285           be called dm-crypt.
 286
 287           If unsure, say N.
 288
 289 config DM_SNAPSHOT
 290        tristate "Snapshot target"
 291        depends on BLK_DEV_DM
 292        select DM_BUFIO
 293        ---help---
 294          Allow volume managers to take writable snapshots of a device.
 295
 296 config DM_THIN_PROVISIONING
 297        tristate "Thin provisioning target"
 298        depends on BLK_DEV_DM
 299        select DM_PERSISTENT_DATA
 300        select DM_BIO_PRISON
 301        ---help---
 302          Provides thin provisioning and snapshots that share a data store.
 303
 304 config DM_CACHE
 305        tristate "Cache target (EXPERIMENTAL)"
 306        depends on BLK_DEV_DM
 307        default n
 308        select DM_PERSISTENT_DATA
 309        select DM_BIO_PRISON
 310        ---help---
 311          dm-cache attempts to improve performance of a block device by
 312          moving frequently used data to a smaller, higher performance
 313          device.  Different 'policy' plugins can be used to change the
 314          algorithms used to select which blocks are promoted, demoted,
 315          cleaned etc.  It supports writeback and writethrough modes.
 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_ERA
 330        tristate "Era target (EXPERIMENTAL)"
 331        depends on BLK_DEV_DM
 332        default n
 333        select DM_PERSISTENT_DATA
 334        select DM_BIO_PRISON
 335        ---help---
 336          dm-era tracks which parts of a block device are written to
 337          over time.  Useful for maintaining cache coherency when using
 338          vendor snapshots.
 339
 340 config DM_MIRROR
 341        tristate "Mirror target"
 342        depends on BLK_DEV_DM
 343        ---help---
 344          Allow volume managers to mirror logical volumes, also
 345          needed for live data migration tools such as 'pvmove'.
 346
 347 config DM_LOG_USERSPACE
 348         tristate "Mirror userspace logging"
 349         depends on DM_MIRROR && NET
 350         select CONNECTOR
 351         ---help---
 352           The userspace logging module provides a mechanism for
 353           relaying the dm-dirty-log API to userspace.  Log designs
 354           which are more suited to userspace implementation (e.g.
 355           shared storage logs) or experimental logs can be implemented
 356           by leveraging this framework.
 357
 358 config DM_RAID
 359        tristate "RAID 1/4/5/6/10 target"
 360        depends on BLK_DEV_DM
 361        select MD_RAID0
 362        select MD_RAID1
 363        select MD_RAID10
 364        select MD_RAID456
 365        select BLK_DEV_MD
 366        ---help---
 367          A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
 368
 369          A RAID-5 set of N drives with a capacity of C MB per drive provides
 370          the capacity of C * (N - 1) MB, and protects against a failure
 371          of a single drive. For a given sector (row) number, (N - 1) drives
 372          contain data sectors, and one drive contains the parity protection.
 373          For a RAID-4 set, the parity blocks are present on a single drive,
 374          while a RAID-5 set distributes the parity across the drives in one
 375          of the available parity distribution methods.
 376
 377          A RAID-6 set of N drives with a capacity of C MB per drive
 378          provides the capacity of C * (N - 2) MB, and protects
 379          against a failure of any two drives. For a given sector
 380          (row) number, (N - 2) drives contain data sectors, and two
 381          drives contains two independent redundancy syndromes.  Like
 382          RAID-5, RAID-6 distributes the syndromes across the drives
 383          in one of the available parity distribution methods.
 384
 385 config DM_ZERO
 386         tristate "Zero target"
 387         depends on BLK_DEV_DM
 388         ---help---
 389           A target that discards writes, and returns all zeroes for
 390           reads.  Useful in some recovery situations.
 391
 392 config DM_MULTIPATH
 393         tristate "Multipath target"
 394         depends on BLK_DEV_DM
 395         # nasty syntax but means make DM_MULTIPATH independent
 396         # of SCSI_DH if the latter isn't defined but if
 397         # it is, DM_MULTIPATH must depend on it.  We get a build
 398         # error if SCSI_DH=m and DM_MULTIPATH=y
 399         depends on !SCSI_DH || SCSI
 400         ---help---
 401           Allow volume managers to support multipath hardware.
 402
 403 config DM_MULTIPATH_QL
 404         tristate "I/O Path Selector based on the number of in-flight I/Os"
 405         depends on DM_MULTIPATH
 406         ---help---
 407           This path selector is a dynamic load balancer which selects
 408           the path with the least number of in-flight I/Os.
 409
 410           If unsure, say N.
 411
 412 config DM_MULTIPATH_ST
 413         tristate "I/O Path Selector based on the service time"
 414         depends on DM_MULTIPATH
 415         ---help---
 416           This path selector is a dynamic load balancer which selects
 417           the path expected to complete the incoming I/O in the shortest
 418           time.
 419
 420           If unsure, say N.
 421
 422 config DM_DELAY
 423         tristate "I/O delaying target"
 424         depends on BLK_DEV_DM
 425         ---help---
 426         A target that delays reads and/or writes and can send
 427         them to different devices.  Useful for testing.
 428
 429         If unsure, say N.
 430
 431 config DM_UEVENT
 432         bool "DM uevents"
 433         depends on BLK_DEV_DM
 434         ---help---
 435         Generate udev events for DM events.
 436
 437 config DM_FLAKEY
 438        tristate "Flakey target"
 439        depends on BLK_DEV_DM
 440        ---help---
 441          A target that intermittently fails I/O for debugging purposes.
 442
 443 config DM_VERITY
 444         tristate "Verity target support"
 445         depends on BLK_DEV_DM
 446         select CRYPTO
 447         select CRYPTO_HASH
 448         select DM_BUFIO
 449         ---help---
 450           This device-mapper target creates a read-only device that
 451           transparently validates the data on one underlying device against
 452           a pre-generated tree of cryptographic checksums stored on a second
 453           device.
 454
 455           You'll need to activate the digests you're going to use in the
 456           cryptoapi configuration.
 457
 458           To compile this code as a module, choose M here: the module will
 459           be called dm-verity.
 460
 461           If unsure, say N.
 462
 463 config DM_VERITY_FEC
 464         bool "Verity forward error correction support"
 465         depends on DM_VERITY
 466         select REED_SOLOMON
 467         select REED_SOLOMON_DEC8
 468         ---help---
 469           Add forward error correction support to dm-verity. This option
 470           makes it possible to use pre-generated error correction data to
 471           recover from corrupted blocks.
 472
 473           If unsure, say N.
 474
 475 config DM_SWITCH
 476         tristate "Switch target support (EXPERIMENTAL)"
 477         depends on BLK_DEV_DM
 478         ---help---
 479           This device-mapper target creates a device that supports an arbitrary
 480           mapping of fixed-size regions of I/O across a fixed set of paths.
 481           The path used for any specific region can be switched dynamically
 482           by sending the target a message.
 483
 484           To compile this code as a module, choose M here: the module will
 485           be called dm-switch.
 486
 487           If unsure, say N.
 488
 489 config DM_LOG_WRITES
 490         tristate "Log writes target support"
 491         depends on BLK_DEV_DM
 492         ---help---
 493           This device-mapper target takes two devices, one device to use
 494           normally, one to log all write operations done to the first device.
 495           This is for use by file system developers wishing to verify that
 496           their fs is writing a consistent file system at all times by allowing
 497           them to replay the log in a variety of ways and to check the
 498           contents.
 499
 500           To compile this code as a module, choose M here: the module will
 501           be called dm-log-writes.
 502
 503           If unsure, say N.
 504
 505 config DM_INTEGRITY
 506         tristate "Integrity target"
 507         depends on BLK_DEV_DM
 508         select BLK_DEV_INTEGRITY
 509         select DM_BUFIO
 510         select CRYPTO
 511         select ASYNC_XOR
 512         ---help---
 513            This is the integrity target.
 514
 515 endif # MD