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 ASYNC_MEMCPY
 127         select ASYNC_XOR
 128         select ASYNC_PQ
 129         select ASYNC_RAID6_RECOV
 130         ---help---
 131           A RAID-5 set of N drives with a capacity of C MB per drive provides
 132           the capacity of C * (N - 1) MB, and protects against a failure
 133           of a single drive. For a given sector (row) number, (N - 1) drives
 134           contain data sectors, and one drive contains the parity protection.
 135           For a RAID-4 set, the parity blocks are present on a single drive,
 136           while a RAID-5 set distributes the parity across the drives in one
 137           of the available parity distribution methods.
 138
 139           A RAID-6 set of N drives with a capacity of C MB per drive
 140           provides the capacity of C * (N - 2) MB, and protects
 141           against a failure of any two drives. For a given sector
 142           (row) number, (N - 2) drives contain data sectors, and two
 143           drives contains two independent redundancy syndromes.  Like
 144           RAID-5, RAID-6 distributes the syndromes across the drives
 145           in one of the available parity distribution methods.
 146
 147           Information about Software RAID on Linux is contained in the
 148           Software-RAID mini-HOWTO, available from
 149           <http://www.tldp.org/docs.html#howto>. There you will also
 150           learn where to get the supporting user space utilities raidtools.
 151
 152           If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y.  To
 153           compile this code as a module, choose M here: the module
 154           will be called raid456.
 155
 156           If unsure, say Y.
 157
 158 config MD_MULTIPATH
 159         tristate "Multipath I/O support"
 160         depends on BLK_DEV_MD
 161         help
 162           MD_MULTIPATH provides a simple multi-path personality for use
 163           the MD framework.  It is not under active development.  New
 164           projects should consider using DM_MULTIPATH which has more
 165           features and more testing.
 166
 167           If unsure, say N.
 168
 169 config MD_FAULTY
 170         tristate "Faulty test module for MD"
 171         depends on BLK_DEV_MD
 172         help
 173           The "faulty" module allows for a block device that occasionally returns
 174           read or write errors.  It is useful for testing.
 175
 176           In unsure, say N.
 177
 178
 179 config MD_CLUSTER
 180         tristate "Cluster Support for MD (EXPERIMENTAL)"
 181         depends on BLK_DEV_MD
 182         depends on DLM
 183         default n
 184         ---help---
 185         Clustering support for MD devices. This enables locking and
 186         synchronization across multiple systems on the cluster, so all
 187         nodes in the cluster can access the MD devices simultaneously.
 188
 189         This brings the redundancy (and uptime) of RAID levels across the
 190         nodes of the cluster.
 191
 192         If unsure, say N.
 193
 194 source "drivers/md/bcache/Kconfig"
 195
 196 config BLK_DEV_DM_BUILTIN
 197         bool
 198
 199 config BLK_DEV_DM
 200         tristate "Device mapper support"
 201         select BLK_DEV_DM_BUILTIN
 202         ---help---
 203           Device-mapper is a low level volume manager.  It works by allowing
 204           people to specify mappings for ranges of logical sectors.  Various
 205           mapping types are available, in addition people may write their own
 206           modules containing custom mappings if they wish.
 207
 208           Higher level volume managers such as LVM2 use this driver.
 209
 210           To compile this as a module, choose M here: the module will be
 211           called dm-mod.
 212
 213           If unsure, say N.
 214
 215 config DM_MQ_DEFAULT
 216         bool "request-based DM: use blk-mq I/O path by default"
 217         depends on BLK_DEV_DM
 218         ---help---
 219           This option enables the blk-mq based I/O path for request-based
 220           DM devices by default.  With the option the dm_mod.use_blk_mq
 221           module/boot option defaults to Y, without it to N, but it can
 222           still be overriden either way.
 223
 224           If unsure say N.
 225
 226 config DM_DEBUG
 227         bool "Device mapper debugging support"
 228         depends on BLK_DEV_DM
 229         ---help---
 230           Enable this for messages that may help debug device-mapper problems.
 231
 232           If unsure, say N.
 233
 234 config DM_BUFIO
 235        tristate
 236        depends on BLK_DEV_DM
 237        ---help---
 238          This interface allows you to do buffered I/O on a device and acts
 239          as a cache, holding recently-read blocks in memory and performing
 240          delayed writes.
 241
 242 config DM_BIO_PRISON
 243        tristate
 244        depends on BLK_DEV_DM
 245        ---help---
 246          Some bio locking schemes used by other device-mapper targets
 247          including thin provisioning.
 248
 249 source "drivers/md/persistent-data/Kconfig"
 250
 251 config DM_CRYPT
 252         tristate "Crypt target support"
 253         depends on BLK_DEV_DM
 254         select CRYPTO
 255         select CRYPTO_CBC
 256         ---help---
 257           This device-mapper target allows you to create a device that
 258           transparently encrypts the data on it. You'll need to activate
 259           the ciphers you're going to use in the cryptoapi configuration.
 260
 261           For further information on dm-crypt and userspace tools see:
 262           <http://code.google.com/p/cryptsetup/wiki/DMCrypt>
 263
 264           To compile this code as a module, choose M here: the module will
 265           be called dm-crypt.
 266
 267           If unsure, say N.
 268
 269 config DM_SNAPSHOT
 270        tristate "Snapshot target"
 271        depends on BLK_DEV_DM
 272        select DM_BUFIO
 273        ---help---
 274          Allow volume managers to take writable snapshots of a device.
 275
 276 config DM_THIN_PROVISIONING
 277        tristate "Thin provisioning target"
 278        depends on BLK_DEV_DM
 279        select DM_PERSISTENT_DATA
 280        select DM_BIO_PRISON
 281        ---help---
 282          Provides thin provisioning and snapshots that share a data store.
 283
 284 config DM_CACHE
 285        tristate "Cache target (EXPERIMENTAL)"
 286        depends on BLK_DEV_DM
 287        default n
 288        select DM_PERSISTENT_DATA
 289        select DM_BIO_PRISON
 290        ---help---
 291          dm-cache attempts to improve performance of a block device by
 292          moving frequently used data to a smaller, higher performance
 293          device.  Different 'policy' plugins can be used to change the
 294          algorithms used to select which blocks are promoted, demoted,
 295          cleaned etc.  It supports writeback and writethrough modes.
 296
 297 config DM_CACHE_MQ
 298        tristate "MQ Cache Policy (EXPERIMENTAL)"
 299        depends on DM_CACHE
 300        default y
 301        ---help---
 302          A cache policy that uses a multiqueue ordered by recent hit
 303          count to select which blocks should be promoted and demoted.
 304          This is meant to be a general purpose policy.  It prioritises
 305          reads over writes.
 306
 307 config DM_CACHE_CLEANER
 308        tristate "Cleaner Cache Policy (EXPERIMENTAL)"
 309        depends on DM_CACHE
 310        default y
 311        ---help---
 312          A simple cache policy that writes back all data to the
 313          origin.  Used when decommissioning a dm-cache.
 314
 315 config DM_ERA
 316        tristate "Era target (EXPERIMENTAL)"
 317        depends on BLK_DEV_DM
 318        default n
 319        select DM_PERSISTENT_DATA
 320        select DM_BIO_PRISON
 321        ---help---
 322          dm-era tracks which parts of a block device are written to
 323          over time.  Useful for maintaining cache coherency when using
 324          vendor snapshots.
 325
 326 config DM_MIRROR
 327        tristate "Mirror target"
 328        depends on BLK_DEV_DM
 329        ---help---
 330          Allow volume managers to mirror logical volumes, also
 331          needed for live data migration tools such as 'pvmove'.
 332
 333 config DM_LOG_USERSPACE
 334         tristate "Mirror userspace logging"
 335         depends on DM_MIRROR && NET
 336         select CONNECTOR
 337         ---help---
 338           The userspace logging module provides a mechanism for
 339           relaying the dm-dirty-log API to userspace.  Log designs
 340           which are more suited to userspace implementation (e.g.
 341           shared storage logs) or experimental logs can be implemented
 342           by leveraging this framework.
 343
 344 config DM_RAID
 345        tristate "RAID 1/4/5/6/10 target"
 346        depends on BLK_DEV_DM
 347        select MD_RAID1
 348        select MD_RAID10
 349        select MD_RAID456
 350        select BLK_DEV_MD
 351        ---help---
 352          A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
 353
 354          A RAID-5 set of N drives with a capacity of C MB per drive provides
 355          the capacity of C * (N - 1) MB, and protects against a failure
 356          of a single drive. For a given sector (row) number, (N - 1) drives
 357          contain data sectors, and one drive contains the parity protection.
 358          For a RAID-4 set, the parity blocks are present on a single drive,
 359          while a RAID-5 set distributes the parity across the drives in one
 360          of the available parity distribution methods.
 361
 362          A RAID-6 set of N drives with a capacity of C MB per drive
 363          provides the capacity of C * (N - 2) MB, and protects
 364          against a failure of any two drives. For a given sector
 365          (row) number, (N - 2) drives contain data sectors, and two
 366          drives contains two independent redundancy syndromes.  Like
 367          RAID-5, RAID-6 distributes the syndromes across the drives
 368          in one of the available parity distribution methods.
 369
 370 config DM_ZERO
 371         tristate "Zero target"
 372         depends on BLK_DEV_DM
 373         ---help---
 374           A target that discards writes, and returns all zeroes for
 375           reads.  Useful in some recovery situations.
 376
 377 config DM_MULTIPATH
 378         tristate "Multipath target"
 379         depends on BLK_DEV_DM
 380         # nasty syntax but means make DM_MULTIPATH independent
 381         # of SCSI_DH if the latter isn't defined but if
 382         # it is, DM_MULTIPATH must depend on it.  We get a build
 383         # error if SCSI_DH=m and DM_MULTIPATH=y
 384         depends on SCSI_DH || !SCSI_DH
 385         ---help---
 386           Allow volume managers to support multipath hardware.
 387
 388 config DM_MULTIPATH_QL
 389         tristate "I/O Path Selector based on the number of in-flight I/Os"
 390         depends on DM_MULTIPATH
 391         ---help---
 392           This path selector is a dynamic load balancer which selects
 393           the path with the least number of in-flight I/Os.
 394
 395           If unsure, say N.
 396
 397 config DM_MULTIPATH_ST
 398         tristate "I/O Path Selector based on the service time"
 399         depends on DM_MULTIPATH
 400         ---help---
 401           This path selector is a dynamic load balancer which selects
 402           the path expected to complete the incoming I/O in the shortest
 403           time.
 404
 405           If unsure, say N.
 406
 407 config DM_DELAY
 408         tristate "I/O delaying target"
 409         depends on BLK_DEV_DM
 410         ---help---
 411         A target that delays reads and/or writes and can send
 412         them to different devices.  Useful for testing.
 413
 414         If unsure, say N.
 415
 416 config DM_UEVENT
 417         bool "DM uevents"
 418         depends on BLK_DEV_DM
 419         ---help---
 420         Generate udev events for DM events.
 421
 422 config DM_FLAKEY
 423        tristate "Flakey target"
 424        depends on BLK_DEV_DM
 425        ---help---
 426          A target that intermittently fails I/O for debugging purposes.
 427
 428 config DM_VERITY
 429         tristate "Verity target support"
 430         depends on BLK_DEV_DM
 431         select CRYPTO
 432         select CRYPTO_HASH
 433         select DM_BUFIO
 434         ---help---
 435           This device-mapper target creates a read-only device that
 436           transparently validates the data on one underlying device against
 437           a pre-generated tree of cryptographic checksums stored on a second
 438           device.
 439
 440           You'll need to activate the digests you're going to use in the
 441           cryptoapi configuration.
 442
 443           To compile this code as a module, choose M here: the module will
 444           be called dm-verity.
 445
 446           If unsure, say N.
 447
 448 config DM_SWITCH
 449         tristate "Switch target support (EXPERIMENTAL)"
 450         depends on BLK_DEV_DM
 451         ---help---
 452           This device-mapper target creates a device that supports an arbitrary
 453           mapping of fixed-size regions of I/O across a fixed set of paths.
 454           The path used for any specific region can be switched dynamically
 455           by sending the target a message.
 456
 457           To compile this code as a module, choose M here: the module will
 458           be called dm-switch.
 459
 460           If unsure, say N.
 461
 462 config DM_LOG_WRITES
 463         tristate "Log writes target support"
 464         depends on BLK_DEV_DM
 465         ---help---
 466           This device-mapper target takes two devices, one device to use
 467           normally, one to log all write operations done to the first device.
 468           This is for use by file system developers wishing to verify that
 469           their fs is writing a consitent file system at all times by allowing
 470           them to replay the log in a variety of ways and to check the
 471           contents.
 472
 473           To compile this code as a module, choose M here: the module will
 474           be called dm-log-writes.
 475
 476           If unsure, say N.
 477
 478 endif # MD