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         help
   9           Support multiple physical spindles through a single logical device.
  10           Required for RAID and logical volume management.
  11
  12 if MD
  13
  14 config BLK_DEV_MD
  15         tristate "RAID support"
  16         ---help---
  17           This driver lets you combine several hard disk partitions into one
  18           logical block device. This can be used to simply append one
  19           partition to another one or to combine several redundant hard disks
  20           into a RAID1/4/5 device so as to provide protection against hard
  21           disk failures. This is called "Software RAID" since the combining of
  22           the partitions is done by the kernel. "Hardware RAID" means that the
  23           combining is done by a dedicated controller; if you have such a
  24           controller, you do not need to say Y here.
  25
  26           More information about Software RAID on Linux is contained in the
  27           Software RAID mini-HOWTO, available from
  28           <http://www.tldp.org/docs.html#howto>. There you will also learn
  29           where to get the supporting user space utilities raidtools.
  30
  31           If unsure, say N.
  32
  33 config MD_AUTODETECT
  34         bool "Autodetect RAID arrays during kernel boot"
  35         depends on BLK_DEV_MD=y
  36         default y
  37         ---help---
  38           If you say Y here, then the kernel will try to autodetect raid
  39           arrays as part of its boot process.
  40
  41           If you don't use raid and say Y, this autodetection can cause
  42           a several-second delay in the boot time due to various
  43           synchronisation steps that are part of this step.
  44
  45           If unsure, say Y.
  46
  47 config MD_LINEAR
  48         tristate "Linear (append) mode"
  49         depends on BLK_DEV_MD
  50         ---help---
  51           If you say Y here, then your multiple devices driver will be able to
  52           use the so-called linear mode, i.e. it will combine the hard disk
  53           partitions by simply appending one to the other.
  54
  55           To compile this as a module, choose M here: the module
  56           will be called linear.
  57
  58           If unsure, say Y.
  59
  60 config MD_RAID0
  61         tristate "RAID-0 (striping) mode"
  62         depends on BLK_DEV_MD
  63         ---help---
  64           If you say Y here, then your multiple devices driver will be able to
  65           use the so-called raid0 mode, i.e. it will combine the hard disk
  66           partitions into one logical device in such a fashion as to fill them
  67           up evenly, one chunk here and one chunk there. This will increase
  68           the throughput rate if the partitions reside on distinct disks.
  69
  70           Information about Software RAID on Linux is contained in the
  71           Software-RAID mini-HOWTO, available from
  72           <http://www.tldp.org/docs.html#howto>. There you will also
  73           learn where to get the supporting user space utilities raidtools.
  74
  75           To compile this as a module, choose M here: the module
  76           will be called raid0.
  77
  78           If unsure, say Y.
  79
  80 config MD_RAID1
  81         tristate "RAID-1 (mirroring) mode"
  82         depends on BLK_DEV_MD
  83         ---help---
  84           A RAID-1 set consists of several disk drives which are exact copies
  85           of each other.  In the event of a mirror failure, the RAID driver
  86           will continue to use the operational mirrors in the set, providing
  87           an error free MD (multiple device) to the higher levels of the
  88           kernel.  In a set with N drives, the available space is the capacity
  89           of a single drive, and the set protects against a failure of (N - 1)
  90           drives.
  91
  92           Information about Software RAID on Linux is contained in the
  93           Software-RAID mini-HOWTO, available from
  94           <http://www.tldp.org/docs.html#howto>.  There you will also
  95           learn where to get the supporting user space utilities raidtools.
  96
  97           If you want to use such a RAID-1 set, say Y.  To compile this code
  98           as a module, choose M here: the module will be called raid1.
  99
 100           If unsure, say Y.
 101
 102 config MD_RAID10
 103         tristate "RAID-10 (mirrored striping) mode"
 104         depends on BLK_DEV_MD
 105         ---help---
 106           RAID-10 provides a combination of striping (RAID-0) and
 107           mirroring (RAID-1) with easier configuration and more flexible
 108           layout.
 109           Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
 110           be the same size (or at least, only as much as the smallest device
 111           will be used).
 112           RAID-10 provides a variety of layouts that provide different levels
 113           of redundancy and performance.
 114
 115           RAID-10 requires mdadm-1.7.0 or later, available at:
 116
 117           ftp://ftp.kernel.org/pub/linux/utils/raid/mdadm/
 118
 119           If unsure, say Y.
 120
 121 config MD_RAID456
 122         tristate "RAID-4/RAID-5/RAID-6 mode"
 123         depends on BLK_DEV_MD
 124         select RAID6_PQ
 125         select ASYNC_MEMCPY
 126         select ASYNC_XOR
 127         select ASYNC_PQ
 128         select ASYNC_RAID6_RECOV
 129         ---help---
 130           A RAID-5 set of N drives with a capacity of C MB per drive provides
 131           the capacity of C * (N - 1) MB, and protects against a failure
 132           of a single drive. For a given sector (row) number, (N - 1) drives
 133           contain data sectors, and one drive contains the parity protection.
 134           For a RAID-4 set, the parity blocks are present on a single drive,
 135           while a RAID-5 set distributes the parity across the drives in one
 136           of the available parity distribution methods.
 137
 138           A RAID-6 set of N drives with a capacity of C MB per drive
 139           provides the capacity of C * (N - 2) MB, and protects
 140           against a failure of any two drives. For a given sector
 141           (row) number, (N - 2) drives contain data sectors, and two
 142           drives contains two independent redundancy syndromes.  Like
 143           RAID-5, RAID-6 distributes the syndromes across the drives
 144           in one of the available parity distribution methods.
 145
 146           Information about Software RAID on Linux is contained in the
 147           Software-RAID mini-HOWTO, available from
 148           <http://www.tldp.org/docs.html#howto>. There you will also
 149           learn where to get the supporting user space utilities raidtools.
 150
 151           If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y.  To
 152           compile this code as a module, choose M here: the module
 153           will be called raid456.
 154
 155           If unsure, say Y.
 156
 157 config MD_MULTIPATH
 158         tristate "Multipath I/O support"
 159         depends on BLK_DEV_MD
 160         help
 161           MD_MULTIPATH provides a simple multi-path personality for use
 162           the MD framework.  It is not under active development.  New
 163           projects should consider using DM_MULTIPATH which has more
 164           features and more testing.
 165
 166           If unsure, say N.
 167
 168 config MD_FAULTY
 169         tristate "Faulty test module for MD"
 170         depends on BLK_DEV_MD
 171         help
 172           The "faulty" module allows for a block device that occasionally returns
 173           read or write errors.  It is useful for testing.
 174
 175           In unsure, say N.
 176
 177 source "drivers/md/bcache/Kconfig"
 178
 179 config BLK_DEV_DM_BUILTIN
 180         boolean
 181
 182 config BLK_DEV_DM
 183         tristate "Device mapper support"
 184         select BLK_DEV_DM_BUILTIN
 185         ---help---
 186           Device-mapper is a low level volume manager.  It works by allowing
 187           people to specify mappings for ranges of logical sectors.  Various
 188           mapping types are available, in addition people may write their own
 189           modules containing custom mappings if they wish.
 190
 191           Higher level volume managers such as LVM2 use this driver.
 192
 193           To compile this as a module, choose M here: the module will be
 194           called dm-mod.
 195
 196           If unsure, say N.
 197
 198 config DM_DEBUG
 199         boolean "Device mapper debugging support"
 200         depends on BLK_DEV_DM
 201         ---help---
 202           Enable this for messages that may help debug device-mapper problems.
 203
 204           If unsure, say N.
 205
 206 config DM_BUFIO
 207        tristate
 208        depends on BLK_DEV_DM
 209        ---help---
 210          This interface allows you to do buffered I/O on a device and acts
 211          as a cache, holding recently-read blocks in memory and performing
 212          delayed writes.
 213
 214 config DM_BIO_PRISON
 215        tristate
 216        depends on BLK_DEV_DM
 217        ---help---
 218          Some bio locking schemes used by other device-mapper targets
 219          including thin provisioning.
 220
 221 source "drivers/md/persistent-data/Kconfig"
 222
 223 config DM_CRYPT
 224         tristate "Crypt target support"
 225         depends on BLK_DEV_DM
 226         select CRYPTO
 227         select CRYPTO_CBC
 228         ---help---
 229           This device-mapper target allows you to create a device that
 230           transparently encrypts the data on it. You'll need to activate
 231           the ciphers you're going to use in the cryptoapi configuration.
 232
 233           Information on how to use dm-crypt can be found on
 234
 235           <http://www.saout.de/misc/dm-crypt/>
 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_DEBUG_BLOCK_STACK_TRACING
 258         boolean "Keep stack trace of persistent data block lock holders"
 259         depends on STACKTRACE_SUPPORT && DM_PERSISTENT_DATA
 260         select STACKTRACE
 261         ---help---
 262           Enable this for messages that may help debug problems with the
 263           block manager locking used by thin provisioning and caching.
 264
 265           If unsure, say N.
 266
 267 config DM_CACHE
 268        tristate "Cache target (EXPERIMENTAL)"
 269        depends on BLK_DEV_DM
 270        default n
 271        select DM_PERSISTENT_DATA
 272        select DM_BIO_PRISON
 273        ---help---
 274          dm-cache attempts to improve performance of a block device by
 275          moving frequently used data to a smaller, higher performance
 276          device.  Different 'policy' plugins can be used to change the
 277          algorithms used to select which blocks are promoted, demoted,
 278          cleaned etc.  It supports writeback and writethrough modes.
 279
 280 config DM_CACHE_MQ
 281        tristate "MQ Cache Policy (EXPERIMENTAL)"
 282        depends on DM_CACHE
 283        default y
 284        ---help---
 285          A cache policy that uses a multiqueue ordered by recent hit
 286          count to select which blocks should be promoted and demoted.
 287          This is meant to be a general purpose policy.  It prioritises
 288          reads over writes.
 289
 290 config DM_CACHE_CLEANER
 291        tristate "Cleaner Cache Policy (EXPERIMENTAL)"
 292        depends on DM_CACHE
 293        default y
 294        ---help---
 295          A simple cache policy that writes back all data to the
 296          origin.  Used when decommissioning a dm-cache.
 297
 298 config DM_MIRROR
 299        tristate "Mirror target"
 300        depends on BLK_DEV_DM
 301        ---help---
 302          Allow volume managers to mirror logical volumes, also
 303          needed for live data migration tools such as 'pvmove'.
 304
 305 config DM_LOG_USERSPACE
 306         tristate "Mirror userspace logging"
 307         depends on DM_MIRROR && NET
 308         select CONNECTOR
 309         ---help---
 310           The userspace logging module provides a mechanism for
 311           relaying the dm-dirty-log API to userspace.  Log designs
 312           which are more suited to userspace implementation (e.g.
 313           shared storage logs) or experimental logs can be implemented
 314           by leveraging this framework.
 315
 316 config DM_RAID
 317        tristate "RAID 1/4/5/6/10 target"
 318        depends on BLK_DEV_DM
 319        select MD_RAID1
 320        select MD_RAID10
 321        select MD_RAID456
 322        select BLK_DEV_MD
 323        ---help---
 324          A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
 325
 326          A RAID-5 set of N drives with a capacity of C MB per drive provides
 327          the capacity of C * (N - 1) MB, and protects against a failure
 328          of a single drive. For a given sector (row) number, (N - 1) drives
 329          contain data sectors, and one drive contains the parity protection.
 330          For a RAID-4 set, the parity blocks are present on a single drive,
 331          while a RAID-5 set distributes the parity across the drives in one
 332          of the available parity distribution methods.
 333
 334          A RAID-6 set of N drives with a capacity of C MB per drive
 335          provides the capacity of C * (N - 2) MB, and protects
 336          against a failure of any two drives. For a given sector
 337          (row) number, (N - 2) drives contain data sectors, and two
 338          drives contains two independent redundancy syndromes.  Like
 339          RAID-5, RAID-6 distributes the syndromes across the drives
 340          in one of the available parity distribution methods.
 341
 342 config DM_ZERO
 343         tristate "Zero target"
 344         depends on BLK_DEV_DM
 345         ---help---
 346           A target that discards writes, and returns all zeroes for
 347           reads.  Useful in some recovery situations.
 348
 349 config DM_MULTIPATH
 350         tristate "Multipath target"
 351         depends on BLK_DEV_DM
 352         # nasty syntax but means make DM_MULTIPATH independent
 353         # of SCSI_DH if the latter isn't defined but if
 354         # it is, DM_MULTIPATH must depend on it.  We get a build
 355         # error if SCSI_DH=m and DM_MULTIPATH=y
 356         depends on SCSI_DH || !SCSI_DH
 357         ---help---
 358           Allow volume managers to support multipath hardware.
 359
 360 config DM_MULTIPATH_QL
 361         tristate "I/O Path Selector based on the number of in-flight I/Os"
 362         depends on DM_MULTIPATH
 363         ---help---
 364           This path selector is a dynamic load balancer which selects
 365           the path with the least number of in-flight I/Os.
 366
 367           If unsure, say N.
 368
 369 config DM_MULTIPATH_ST
 370         tristate "I/O Path Selector based on the service time"
 371         depends on DM_MULTIPATH
 372         ---help---
 373           This path selector is a dynamic load balancer which selects
 374           the path expected to complete the incoming I/O in the shortest
 375           time.
 376
 377           If unsure, say N.
 378
 379 config DM_DELAY
 380         tristate "I/O delaying target"
 381         depends on BLK_DEV_DM
 382         ---help---
 383         A target that delays reads and/or writes and can send
 384         them to different devices.  Useful for testing.
 385
 386         If unsure, say N.
 387
 388 config DM_UEVENT
 389         bool "DM uevents"
 390         depends on BLK_DEV_DM
 391         ---help---
 392         Generate udev events for DM events.
 393
 394 config DM_FLAKEY
 395        tristate "Flakey target"
 396        depends on BLK_DEV_DM
 397        ---help---
 398          A target that intermittently fails I/O for debugging purposes.
 399
 400 config DM_VERITY
 401         tristate "Verity target support"
 402         depends on BLK_DEV_DM
 403         select CRYPTO
 404         select CRYPTO_HASH
 405         select DM_BUFIO
 406         ---help---
 407           This device-mapper target creates a read-only device that
 408           transparently validates the data on one underlying device against
 409           a pre-generated tree of cryptographic checksums stored on a second
 410           device.
 411
 412           You'll need to activate the digests you're going to use in the
 413           cryptoapi configuration.
 414
 415           To compile this code as a module, choose M here: the module will
 416           be called dm-verity.
 417
 418           If unsure, say N.
 419
 420 config DM_SWITCH
 421         tristate "Switch target support (EXPERIMENTAL)"
 422         depends on BLK_DEV_DM
 423         ---help---
 424           This device-mapper target creates a device that supports an arbitrary
 425           mapping of fixed-size regions of I/O across a fixed set of paths.
 426           The path used for any specific region can be switched dynamically
 427           by sending the target a message.
 428
 429           To compile this code as a module, choose M here: the module will
 430           be called dm-switch.
 431
 432           If unsure, say N.
 433
 434 endif # MD