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