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