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_DEBUG
 216         bool "Device mapper debugging support"
 217         depends on BLK_DEV_DM
 218         ---help---
 219           Enable this for messages that may help debug device-mapper problems.
 220
 221           If unsure, say N.
 222
 223 config DM_BUFIO
 224        tristate
 225        depends on BLK_DEV_DM
 226        ---help---
 227          This interface allows you to do buffered I/O on a device and acts
 228          as a cache, holding recently-read blocks in memory and performing
 229          delayed writes.
 230
 231 config DM_BIO_PRISON
 232        tristate
 233        depends on BLK_DEV_DM
 234        ---help---
 235          Some bio locking schemes used by other device-mapper targets
 236          including thin provisioning.
 237
 238 source "drivers/md/persistent-data/Kconfig"
 239
 240 config DM_CRYPT
 241         tristate "Crypt target support"
 242         depends on BLK_DEV_DM
 243         select CRYPTO
 244         select CRYPTO_CBC
 245         ---help---
 246           This device-mapper target allows you to create a device that
 247           transparently encrypts the data on it. You'll need to activate
 248           the ciphers you're going to use in the cryptoapi configuration.
 249
 250           For further information on dm-crypt and userspace tools see:
 251           <http://code.google.com/p/cryptsetup/wiki/DMCrypt>
 252
 253           To compile this code as a module, choose M here: the module will
 254           be called dm-crypt.
 255
 256           If unsure, say N.
 257
 258 config DM_SNAPSHOT
 259        tristate "Snapshot target"
 260        depends on BLK_DEV_DM
 261        select DM_BUFIO
 262        ---help---
 263          Allow volume managers to take writable snapshots of a device.
 264
 265 config DM_THIN_PROVISIONING
 266        tristate "Thin provisioning target"
 267        depends on BLK_DEV_DM
 268        select DM_PERSISTENT_DATA
 269        select DM_BIO_PRISON
 270        ---help---
 271          Provides thin provisioning and snapshots that share a data store.
 272
 273 config DM_CACHE
 274        tristate "Cache target (EXPERIMENTAL)"
 275        depends on BLK_DEV_DM
 276        default n
 277        select DM_PERSISTENT_DATA
 278        select DM_BIO_PRISON
 279        ---help---
 280          dm-cache attempts to improve performance of a block device by
 281          moving frequently used data to a smaller, higher performance
 282          device.  Different 'policy' plugins can be used to change the
 283          algorithms used to select which blocks are promoted, demoted,
 284          cleaned etc.  It supports writeback and writethrough modes.
 285
 286 config DM_CACHE_MQ
 287        tristate "MQ Cache Policy (EXPERIMENTAL)"
 288        depends on DM_CACHE
 289        default y
 290        ---help---
 291          A cache policy that uses a multiqueue ordered by recent hit
 292          count to select which blocks should be promoted and demoted.
 293          This is meant to be a general purpose policy.  It prioritises
 294          reads over writes.
 295
 296 config DM_CACHE_CLEANER
 297        tristate "Cleaner Cache Policy (EXPERIMENTAL)"
 298        depends on DM_CACHE
 299        default y
 300        ---help---
 301          A simple cache policy that writes back all data to the
 302          origin.  Used when decommissioning a dm-cache.
 303
 304 config DM_ERA
 305        tristate "Era 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-era tracks which parts of a block device are written to
 312          over time.  Useful for maintaining cache coherency when using
 313          vendor snapshots.
 314
 315 config DM_MIRROR
 316        tristate "Mirror target"
 317        depends on BLK_DEV_DM
 318        ---help---
 319          Allow volume managers to mirror logical volumes, also
 320          needed for live data migration tools such as 'pvmove'.
 321
 322 config DM_LOG_USERSPACE
 323         tristate "Mirror userspace logging"
 324         depends on DM_MIRROR && NET
 325         select CONNECTOR
 326         ---help---
 327           The userspace logging module provides a mechanism for
 328           relaying the dm-dirty-log API to userspace.  Log designs
 329           which are more suited to userspace implementation (e.g.
 330           shared storage logs) or experimental logs can be implemented
 331           by leveraging this framework.
 332
 333 config DM_RAID
 334        tristate "RAID 1/4/5/6/10 target"
 335        depends on BLK_DEV_DM
 336        select MD_RAID1
 337        select MD_RAID10
 338        select MD_RAID456
 339        select BLK_DEV_MD
 340        ---help---
 341          A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
 342
 343          A RAID-5 set of N drives with a capacity of C MB per drive provides
 344          the capacity of C * (N - 1) MB, and protects against a failure
 345          of a single drive. For a given sector (row) number, (N - 1) drives
 346          contain data sectors, and one drive contains the parity protection.
 347          For a RAID-4 set, the parity blocks are present on a single drive,
 348          while a RAID-5 set distributes the parity across the drives in one
 349          of the available parity distribution methods.
 350
 351          A RAID-6 set of N drives with a capacity of C MB per drive
 352          provides the capacity of C * (N - 2) MB, and protects
 353          against a failure of any two drives. For a given sector
 354          (row) number, (N - 2) drives contain data sectors, and two
 355          drives contains two independent redundancy syndromes.  Like
 356          RAID-5, RAID-6 distributes the syndromes across the drives
 357          in one of the available parity distribution methods.
 358
 359 config DM_ZERO
 360         tristate "Zero target"
 361         depends on BLK_DEV_DM
 362         ---help---
 363           A target that discards writes, and returns all zeroes for
 364           reads.  Useful in some recovery situations.
 365
 366 config DM_MULTIPATH
 367         tristate "Multipath target"
 368         depends on BLK_DEV_DM
 369         # nasty syntax but means make DM_MULTIPATH independent
 370         # of SCSI_DH if the latter isn't defined but if
 371         # it is, DM_MULTIPATH must depend on it.  We get a build
 372         # error if SCSI_DH=m and DM_MULTIPATH=y
 373         depends on SCSI_DH || !SCSI_DH
 374         ---help---
 375           Allow volume managers to support multipath hardware.
 376
 377 config DM_MULTIPATH_QL
 378         tristate "I/O Path Selector based on the number of in-flight I/Os"
 379         depends on DM_MULTIPATH
 380         ---help---
 381           This path selector is a dynamic load balancer which selects
 382           the path with the least number of in-flight I/Os.
 383
 384           If unsure, say N.
 385
 386 config DM_MULTIPATH_ST
 387         tristate "I/O Path Selector based on the service time"
 388         depends on DM_MULTIPATH
 389         ---help---
 390           This path selector is a dynamic load balancer which selects
 391           the path expected to complete the incoming I/O in the shortest
 392           time.
 393
 394           If unsure, say N.
 395
 396 config DM_DELAY
 397         tristate "I/O delaying target"
 398         depends on BLK_DEV_DM
 399         ---help---
 400         A target that delays reads and/or writes and can send
 401         them to different devices.  Useful for testing.
 402
 403         If unsure, say N.
 404
 405 config DM_UEVENT
 406         bool "DM uevents"
 407         depends on BLK_DEV_DM
 408         ---help---
 409         Generate udev events for DM events.
 410
 411 config DM_FLAKEY
 412        tristate "Flakey target"
 413        depends on BLK_DEV_DM
 414        ---help---
 415          A target that intermittently fails I/O for debugging purposes.
 416
 417 config DM_VERITY
 418         tristate "Verity target support"
 419         depends on BLK_DEV_DM
 420         select CRYPTO
 421         select CRYPTO_HASH
 422         select DM_BUFIO
 423         ---help---
 424           This device-mapper target creates a read-only device that
 425           transparently validates the data on one underlying device against
 426           a pre-generated tree of cryptographic checksums stored on a second
 427           device.
 428
 429           You'll need to activate the digests you're going to use in the
 430           cryptoapi configuration.
 431
 432           To compile this code as a module, choose M here: the module will
 433           be called dm-verity.
 434
 435           If unsure, say N.
 436
 437 config DM_SWITCH
 438         tristate "Switch target support (EXPERIMENTAL)"
 439         depends on BLK_DEV_DM
 440         ---help---
 441           This device-mapper target creates a device that supports an arbitrary
 442           mapping of fixed-size regions of I/O across a fixed set of paths.
 443           The path used for any specific region can be switched dynamically
 444           by sending the target a message.
 445
 446           To compile this code as a module, choose M here: the module will
 447           be called dm-switch.
 448
 449           If unsure, say N.
 450
 451 endif # MD