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 source "drivers/md/bcache/Kconfig"
 179
 180 config BLK_DEV_DM_BUILTIN
 181         bool
 182
 183 config BLK_DEV_DM
 184         tristate "Device mapper support"
 185         select BLK_DEV_DM_BUILTIN
 186         ---help---
 187           Device-mapper is a low level volume manager.  It works by allowing
 188           people to specify mappings for ranges of logical sectors.  Various
 189           mapping types are available, in addition people may write their own
 190           modules containing custom mappings if they wish.
 191
 192           Higher level volume managers such as LVM2 use this driver.
 193
 194           To compile this as a module, choose M here: the module will be
 195           called dm-mod.
 196
 197           If unsure, say N.
 198
 199 config DM_DEBUG
 200         bool "Device mapper debugging support"
 201         depends on BLK_DEV_DM
 202         ---help---
 203           Enable this for messages that may help debug device-mapper problems.
 204
 205           If unsure, say N.
 206
 207 config DM_BUFIO
 208        tristate
 209        depends on BLK_DEV_DM
 210        ---help---
 211          This interface allows you to do buffered I/O on a device and acts
 212          as a cache, holding recently-read blocks in memory and performing
 213          delayed writes.
 214
 215 config DM_BIO_PRISON
 216        tristate
 217        depends on BLK_DEV_DM
 218        ---help---
 219          Some bio locking schemes used by other device-mapper targets
 220          including thin provisioning.
 221
 222 source "drivers/md/persistent-data/Kconfig"
 223
 224 config DM_CRYPT
 225         tristate "Crypt target support"
 226         depends on BLK_DEV_DM
 227         select CRYPTO
 228         select CRYPTO_CBC
 229         ---help---
 230           This device-mapper target allows you to create a device that
 231           transparently encrypts the data on it. You'll need to activate
 232           the ciphers you're going to use in the cryptoapi configuration.
 233
 234           For further information on dm-crypt and userspace tools see:
 235           <http://code.google.com/p/cryptsetup/wiki/DMCrypt>
 236
 237           To compile this code as a module, choose M here: the module will
 238           be called dm-crypt.
 239
 240           If unsure, say N.
 241
 242 config DM_SNAPSHOT
 243        tristate "Snapshot target"
 244        depends on BLK_DEV_DM
 245        select DM_BUFIO
 246        ---help---
 247          Allow volume managers to take writable snapshots of a device.
 248
 249 config DM_THIN_PROVISIONING
 250        tristate "Thin provisioning target"
 251        depends on BLK_DEV_DM
 252        select DM_PERSISTENT_DATA
 253        select DM_BIO_PRISON
 254        ---help---
 255          Provides thin provisioning and snapshots that share a data store.
 256
 257 config DM_CACHE
 258        tristate "Cache target (EXPERIMENTAL)"
 259        depends on BLK_DEV_DM
 260        default n
 261        select DM_PERSISTENT_DATA
 262        select DM_BIO_PRISON
 263        ---help---
 264          dm-cache attempts to improve performance of a block device by
 265          moving frequently used data to a smaller, higher performance
 266          device.  Different 'policy' plugins can be used to change the
 267          algorithms used to select which blocks are promoted, demoted,
 268          cleaned etc.  It supports writeback and writethrough modes.
 269
 270 config DM_CACHE_MQ
 271        tristate "MQ Cache Policy (EXPERIMENTAL)"
 272        depends on DM_CACHE
 273        default y
 274        ---help---
 275          A cache policy that uses a multiqueue ordered by recent hit
 276          count to select which blocks should be promoted and demoted.
 277          This is meant to be a general purpose policy.  It prioritises
 278          reads over writes.
 279
 280 config DM_CACHE_CLEANER
 281        tristate "Cleaner Cache Policy (EXPERIMENTAL)"
 282        depends on DM_CACHE
 283        default y
 284        ---help---
 285          A simple cache policy that writes back all data to the
 286          origin.  Used when decommissioning a dm-cache.
 287
 288 config DM_ERA
 289        tristate "Era target (EXPERIMENTAL)"
 290        depends on BLK_DEV_DM
 291        default n
 292        select DM_PERSISTENT_DATA
 293        select DM_BIO_PRISON
 294        ---help---
 295          dm-era tracks which parts of a block device are written to
 296          over time.  Useful for maintaining cache coherency when using
 297          vendor snapshots.
 298
 299 config DM_MIRROR
 300        tristate "Mirror target"
 301        depends on BLK_DEV_DM
 302        ---help---
 303          Allow volume managers to mirror logical volumes, also
 304          needed for live data migration tools such as 'pvmove'.
 305
 306 config DM_LOG_USERSPACE
 307         tristate "Mirror userspace logging"
 308         depends on DM_MIRROR && NET
 309         select CONNECTOR
 310         ---help---
 311           The userspace logging module provides a mechanism for
 312           relaying the dm-dirty-log API to userspace.  Log designs
 313           which are more suited to userspace implementation (e.g.
 314           shared storage logs) or experimental logs can be implemented
 315           by leveraging this framework.
 316
 317 config DM_RAID
 318        tristate "RAID 1/4/5/6/10 target"
 319        depends on BLK_DEV_DM
 320        select MD_RAID1
 321        select MD_RAID10
 322        select MD_RAID456
 323        select BLK_DEV_MD
 324        ---help---
 325          A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
 326
 327          A RAID-5 set of N drives with a capacity of C MB per drive provides
 328          the capacity of C * (N - 1) MB, and protects against a failure
 329          of a single drive. For a given sector (row) number, (N - 1) drives
 330          contain data sectors, and one drive contains the parity protection.
 331          For a RAID-4 set, the parity blocks are present on a single drive,
 332          while a RAID-5 set distributes the parity across the drives in one
 333          of the available parity distribution methods.
 334
 335          A RAID-6 set of N drives with a capacity of C MB per drive
 336          provides the capacity of C * (N - 2) MB, and protects
 337          against a failure of any two drives. For a given sector
 338          (row) number, (N - 2) drives contain data sectors, and two
 339          drives contains two independent redundancy syndromes.  Like
 340          RAID-5, RAID-6 distributes the syndromes across the drives
 341          in one of the available parity distribution methods.
 342
 343 config DM_ZERO
 344         tristate "Zero target"
 345         depends on BLK_DEV_DM
 346         ---help---
 347           A target that discards writes, and returns all zeroes for
 348           reads.  Useful in some recovery situations.
 349
 350 config DM_MULTIPATH
 351         tristate "Multipath target"
 352         depends on BLK_DEV_DM
 353         # nasty syntax but means make DM_MULTIPATH independent
 354         # of SCSI_DH if the latter isn't defined but if
 355         # it is, DM_MULTIPATH must depend on it.  We get a build
 356         # error if SCSI_DH=m and DM_MULTIPATH=y
 357         depends on SCSI_DH || !SCSI_DH
 358         ---help---
 359           Allow volume managers to support multipath hardware.
 360
 361 config DM_MULTIPATH_QL
 362         tristate "I/O Path Selector based on the number of in-flight I/Os"
 363         depends on DM_MULTIPATH
 364         ---help---
 365           This path selector is a dynamic load balancer which selects
 366           the path with the least number of in-flight I/Os.
 367
 368           If unsure, say N.
 369
 370 config DM_MULTIPATH_ST
 371         tristate "I/O Path Selector based on the service time"
 372         depends on DM_MULTIPATH
 373         ---help---
 374           This path selector is a dynamic load balancer which selects
 375           the path expected to complete the incoming I/O in the shortest
 376           time.
 377
 378           If unsure, say N.
 379
 380 config DM_DELAY
 381         tristate "I/O delaying target"
 382         depends on BLK_DEV_DM
 383         ---help---
 384         A target that delays reads and/or writes and can send
 385         them to different devices.  Useful for testing.
 386
 387         If unsure, say N.
 388
 389 config DM_UEVENT
 390         bool "DM uevents"
 391         depends on BLK_DEV_DM
 392         ---help---
 393         Generate udev events for DM events.
 394
 395 config DM_FLAKEY
 396        tristate "Flakey target"
 397        depends on BLK_DEV_DM
 398        ---help---
 399          A target that intermittently fails I/O for debugging purposes.
 400
 401 config DM_VERITY
 402         tristate "Verity target support"
 403         depends on BLK_DEV_DM
 404         select CRYPTO
 405         select CRYPTO_HASH
 406         select DM_BUFIO
 407         ---help---
 408           This device-mapper target creates a read-only device that
 409           transparently validates the data on one underlying device against
 410           a pre-generated tree of cryptographic checksums stored on a second
 411           device.
 412
 413           You'll need to activate the digests you're going to use in the
 414           cryptoapi configuration.
 415
 416           To compile this code as a module, choose M here: the module will
 417           be called dm-verity.
 418
 419           If unsure, say N.
 420
 421 config DM_SWITCH
 422         tristate "Switch target support (EXPERIMENTAL)"
 423         depends on BLK_DEV_DM
 424         ---help---
 425           This device-mapper target creates a device that supports an arbitrary
 426           mapping of fixed-size regions of I/O across a fixed set of paths.
 427           The path used for any specific region can be switched dynamically
 428           by sending the target a message.
 429
 430           To compile this code as a module, choose M here: the module will
 431           be called dm-switch.
 432
 433           If unsure, say N.
 434
 435 endif # MD