Loading...
1# SPDX-License-Identifier: GPL-2.0-only
2#
3# Block device driver configuration
4#
5
6menuconfig MD
7 bool "Multiple devices driver support (RAID and LVM)"
8 depends on BLOCK
9 select SRCU
10 help
11 Support multiple physical spindles through a single logical device.
12 Required for RAID and logical volume management.
13
14if MD
15
16config BLK_DEV_MD
17 tristate "RAID support"
18 select BLOCK_HOLDER_DEPRECATED if SYSFS
19 help
20 This driver lets you combine several hard disk partitions into one
21 logical block device. This can be used to simply append one
22 partition to another one or to combine several redundant hard disks
23 into a RAID1/4/5 device so as to provide protection against hard
24 disk failures. This is called "Software RAID" since the combining of
25 the partitions is done by the kernel. "Hardware RAID" means that the
26 combining is done by a dedicated controller; if you have such a
27 controller, you do not need to say Y here.
28
29 More information about Software RAID on Linux is contained in the
30 Software RAID mini-HOWTO, available from
31 <https://www.tldp.org/docs.html#howto>. There you will also learn
32 where to get the supporting user space utilities raidtools.
33
34 If unsure, say N.
35
36config MD_AUTODETECT
37 bool "Autodetect RAID arrays during kernel boot"
38 depends on BLK_DEV_MD=y
39 default y
40 help
41 If you say Y here, then the kernel will try to autodetect raid
42 arrays as part of its boot process.
43
44 If you don't use raid and say Y, this autodetection can cause
45 a several-second delay in the boot time due to various
46 synchronisation steps that are part of this step.
47
48 If unsure, say Y.
49
50config MD_LINEAR
51 tristate "Linear (append) mode (deprecated)"
52 depends on BLK_DEV_MD
53 help
54 If you say Y here, then your multiple devices driver will be able to
55 use the so-called linear mode, i.e. it will combine the hard disk
56 partitions by simply appending one to the other.
57
58 To compile this as a module, choose M here: the module
59 will be called linear.
60
61 If unsure, say Y.
62
63config MD_RAID0
64 tristate "RAID-0 (striping) mode"
65 depends on BLK_DEV_MD
66 help
67 If you say Y here, then your multiple devices driver will be able to
68 use the so-called raid0 mode, i.e. it will combine the hard disk
69 partitions into one logical device in such a fashion as to fill them
70 up evenly, one chunk here and one chunk there. This will increase
71 the throughput rate if the partitions reside on distinct disks.
72
73 Information about Software RAID on Linux is contained in the
74 Software-RAID mini-HOWTO, available from
75 <https://www.tldp.org/docs.html#howto>. There you will also
76 learn where to get the supporting user space utilities raidtools.
77
78 To compile this as a module, choose M here: the module
79 will be called raid0.
80
81 If unsure, say Y.
82
83config MD_RAID1
84 tristate "RAID-1 (mirroring) mode"
85 depends on BLK_DEV_MD
86 help
87 A RAID-1 set consists of several disk drives which are exact copies
88 of each other. In the event of a mirror failure, the RAID driver
89 will continue to use the operational mirrors in the set, providing
90 an error free MD (multiple device) to the higher levels of the
91 kernel. In a set with N drives, the available space is the capacity
92 of a single drive, and the set protects against a failure of (N - 1)
93 drives.
94
95 Information about Software RAID on Linux is contained in the
96 Software-RAID mini-HOWTO, available from
97 <https://www.tldp.org/docs.html#howto>. There you will also
98 learn where to get the supporting user space utilities raidtools.
99
100 If you want to use such a RAID-1 set, say Y. To compile this code
101 as a module, choose M here: the module will be called raid1.
102
103 If unsure, say Y.
104
105config MD_RAID10
106 tristate "RAID-10 (mirrored striping) mode"
107 depends on BLK_DEV_MD
108 help
109 RAID-10 provides a combination of striping (RAID-0) and
110 mirroring (RAID-1) with easier configuration and more flexible
111 layout.
112 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
113 be the same size (or at least, only as much as the smallest device
114 will be used).
115 RAID-10 provides a variety of layouts that provide different levels
116 of redundancy and performance.
117
118 RAID-10 requires mdadm-1.7.0 or later, available at:
119
120 https://www.kernel.org/pub/linux/utils/raid/mdadm/
121
122 If unsure, say Y.
123
124config MD_RAID456
125 tristate "RAID-4/RAID-5/RAID-6 mode"
126 depends on BLK_DEV_MD
127 select RAID6_PQ
128 select LIBCRC32C
129 select ASYNC_MEMCPY
130 select ASYNC_XOR
131 select ASYNC_PQ
132 select ASYNC_RAID6_RECOV
133 help
134 A RAID-5 set of N drives with a capacity of C MB per drive provides
135 the capacity of C * (N - 1) MB, and protects against a failure
136 of a single drive. For a given sector (row) number, (N - 1) drives
137 contain data sectors, and one drive contains the parity protection.
138 For a RAID-4 set, the parity blocks are present on a single drive,
139 while a RAID-5 set distributes the parity across the drives in one
140 of the available parity distribution methods.
141
142 A RAID-6 set of N drives with a capacity of C MB per drive
143 provides the capacity of C * (N - 2) MB, and protects
144 against a failure of any two drives. For a given sector
145 (row) number, (N - 2) drives contain data sectors, and two
146 drives contains two independent redundancy syndromes. Like
147 RAID-5, RAID-6 distributes the syndromes across the drives
148 in one of the available parity distribution methods.
149
150 Information about Software RAID on Linux is contained in the
151 Software-RAID mini-HOWTO, available from
152 <https://www.tldp.org/docs.html#howto>. There you will also
153 learn where to get the supporting user space utilities raidtools.
154
155 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To
156 compile this code as a module, choose M here: the module
157 will be called raid456.
158
159 If unsure, say Y.
160
161config MD_MULTIPATH
162 tristate "Multipath I/O support (deprecated)"
163 depends on BLK_DEV_MD
164 help
165 MD_MULTIPATH provides a simple multi-path personality for use
166 the MD framework. It is not under active development. New
167 projects should consider using DM_MULTIPATH which has more
168 features and more testing.
169
170 If unsure, say N.
171
172config MD_FAULTY
173 tristate "Faulty test module for MD (deprecated)"
174 depends on BLK_DEV_MD
175 help
176 The "faulty" module allows for a block device that occasionally returns
177 read or write errors. It is useful for testing.
178
179 In unsure, say N.
180
181
182config MD_CLUSTER
183 tristate "Cluster Support for MD"
184 depends on BLK_DEV_MD
185 depends on DLM
186 default n
187 help
188 Clustering support for MD devices. This enables locking and
189 synchronization across multiple systems on the cluster, so all
190 nodes in the cluster can access the MD devices simultaneously.
191
192 This brings the redundancy (and uptime) of RAID levels across the
193 nodes of the cluster. Currently, it can work with raid1 and raid10
194 (limited support).
195
196 If unsure, say N.
197
198source "drivers/md/bcache/Kconfig"
199
200config BLK_DEV_DM_BUILTIN
201 bool
202
203config BLK_DEV_DM
204 tristate "Device mapper support"
205 select BLOCK_HOLDER_DEPRECATED if SYSFS
206 select BLK_DEV_DM_BUILTIN
207 select BLK_MQ_STACKING
208 depends on DAX || DAX=n
209 help
210 Device-mapper is a low level volume manager. It works by allowing
211 people to specify mappings for ranges of logical sectors. Various
212 mapping types are available, in addition people may write their own
213 modules containing custom mappings if they wish.
214
215 Higher level volume managers such as LVM2 use this driver.
216
217 To compile this as a module, choose M here: the module will be
218 called dm-mod.
219
220 If unsure, say N.
221
222config DM_DEBUG
223 bool "Device mapper debugging support"
224 depends on BLK_DEV_DM
225 help
226 Enable this for messages that may help debug device-mapper problems.
227
228 If unsure, say N.
229
230config DM_BUFIO
231 tristate
232 depends on BLK_DEV_DM
233 help
234 This interface allows you to do buffered I/O on a device and acts
235 as a cache, holding recently-read blocks in memory and performing
236 delayed writes.
237
238config DM_DEBUG_BLOCK_MANAGER_LOCKING
239 bool "Block manager locking"
240 depends on DM_BUFIO
241 help
242 Block manager locking can catch various metadata corruption issues.
243
244 If unsure, say N.
245
246config DM_DEBUG_BLOCK_STACK_TRACING
247 bool "Keep stack trace of persistent data block lock holders"
248 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
249 select STACKTRACE
250 help
251 Enable this for messages that may help debug problems with the
252 block manager locking used by thin provisioning and caching.
253
254 If unsure, say N.
255
256config DM_BIO_PRISON
257 tristate
258 depends on BLK_DEV_DM
259 help
260 Some bio locking schemes used by other device-mapper targets
261 including thin provisioning.
262
263source "drivers/md/persistent-data/Kconfig"
264
265config DM_UNSTRIPED
266 tristate "Unstriped target"
267 depends on BLK_DEV_DM
268 help
269 Unstripes I/O so it is issued solely on a single drive in a HW
270 RAID0 or dm-striped target.
271
272config DM_CRYPT
273 tristate "Crypt target support"
274 depends on BLK_DEV_DM
275 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n)
276 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n)
277 select CRYPTO
278 select CRYPTO_CBC
279 select CRYPTO_ESSIV
280 help
281 This device-mapper target allows you to create a device that
282 transparently encrypts the data on it. You'll need to activate
283 the ciphers you're going to use in the cryptoapi configuration.
284
285 For further information on dm-crypt and userspace tools see:
286 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
287
288 To compile this code as a module, choose M here: the module will
289 be called dm-crypt.
290
291 If unsure, say N.
292
293config DM_SNAPSHOT
294 tristate "Snapshot target"
295 depends on BLK_DEV_DM
296 select DM_BUFIO
297 help
298 Allow volume managers to take writable snapshots of a device.
299
300config DM_THIN_PROVISIONING
301 tristate "Thin provisioning target"
302 depends on BLK_DEV_DM
303 select DM_PERSISTENT_DATA
304 select DM_BIO_PRISON
305 help
306 Provides thin provisioning and snapshots that share a data store.
307
308config DM_CACHE
309 tristate "Cache target (EXPERIMENTAL)"
310 depends on BLK_DEV_DM
311 default n
312 select DM_PERSISTENT_DATA
313 select DM_BIO_PRISON
314 help
315 dm-cache attempts to improve performance of a block device by
316 moving frequently used data to a smaller, higher performance
317 device. Different 'policy' plugins can be used to change the
318 algorithms used to select which blocks are promoted, demoted,
319 cleaned etc. It supports writeback and writethrough modes.
320
321config DM_CACHE_SMQ
322 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
323 depends on DM_CACHE
324 default y
325 help
326 A cache policy that uses a multiqueue ordered by recent hits
327 to select which blocks should be promoted and demoted.
328 This is meant to be a general purpose policy. It prioritises
329 reads over writes. This SMQ policy (vs MQ) offers the promise
330 of less memory utilization, improved performance and increased
331 adaptability in the face of changing workloads.
332
333config DM_WRITECACHE
334 tristate "Writecache target"
335 depends on BLK_DEV_DM
336 help
337 The writecache target caches writes on persistent memory or SSD.
338 It is intended for databases or other programs that need extremely
339 low commit latency.
340
341 The writecache target doesn't cache reads because reads are supposed
342 to be cached in standard RAM.
343
344config DM_EBS
345 tristate "Emulated block size target (EXPERIMENTAL)"
346 depends on BLK_DEV_DM && !HIGHMEM
347 select DM_BUFIO
348 help
349 dm-ebs emulates smaller logical block size on backing devices
350 with larger ones (e.g. 512 byte sectors on 4K native disks).
351
352config DM_ERA
353 tristate "Era target (EXPERIMENTAL)"
354 depends on BLK_DEV_DM
355 default n
356 select DM_PERSISTENT_DATA
357 select DM_BIO_PRISON
358 help
359 dm-era tracks which parts of a block device are written to
360 over time. Useful for maintaining cache coherency when using
361 vendor snapshots.
362
363config DM_CLONE
364 tristate "Clone target (EXPERIMENTAL)"
365 depends on BLK_DEV_DM
366 default n
367 select DM_PERSISTENT_DATA
368 help
369 dm-clone produces a one-to-one copy of an existing, read-only source
370 device into a writable destination device. The cloned device is
371 visible/mountable immediately and the copy of the source device to the
372 destination device happens in the background, in parallel with user
373 I/O.
374
375 If unsure, say N.
376
377config DM_MIRROR
378 tristate "Mirror target"
379 depends on BLK_DEV_DM
380 help
381 Allow volume managers to mirror logical volumes, also
382 needed for live data migration tools such as 'pvmove'.
383
384config DM_LOG_USERSPACE
385 tristate "Mirror userspace logging"
386 depends on DM_MIRROR && NET
387 select CONNECTOR
388 help
389 The userspace logging module provides a mechanism for
390 relaying the dm-dirty-log API to userspace. Log designs
391 which are more suited to userspace implementation (e.g.
392 shared storage logs) or experimental logs can be implemented
393 by leveraging this framework.
394
395config DM_RAID
396 tristate "RAID 1/4/5/6/10 target"
397 depends on BLK_DEV_DM
398 select MD_RAID0
399 select MD_RAID1
400 select MD_RAID10
401 select MD_RAID456
402 select BLK_DEV_MD
403 help
404 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
405
406 A RAID-5 set of N drives with a capacity of C MB per drive provides
407 the capacity of C * (N - 1) MB, and protects against a failure
408 of a single drive. For a given sector (row) number, (N - 1) drives
409 contain data sectors, and one drive contains the parity protection.
410 For a RAID-4 set, the parity blocks are present on a single drive,
411 while a RAID-5 set distributes the parity across the drives in one
412 of the available parity distribution methods.
413
414 A RAID-6 set of N drives with a capacity of C MB per drive
415 provides the capacity of C * (N - 2) MB, and protects
416 against a failure of any two drives. For a given sector
417 (row) number, (N - 2) drives contain data sectors, and two
418 drives contains two independent redundancy syndromes. Like
419 RAID-5, RAID-6 distributes the syndromes across the drives
420 in one of the available parity distribution methods.
421
422config DM_ZERO
423 tristate "Zero target"
424 depends on BLK_DEV_DM
425 help
426 A target that discards writes, and returns all zeroes for
427 reads. Useful in some recovery situations.
428
429config DM_MULTIPATH
430 tristate "Multipath target"
431 depends on BLK_DEV_DM
432 # nasty syntax but means make DM_MULTIPATH independent
433 # of SCSI_DH if the latter isn't defined but if
434 # it is, DM_MULTIPATH must depend on it. We get a build
435 # error if SCSI_DH=m and DM_MULTIPATH=y
436 depends on !SCSI_DH || SCSI
437 help
438 Allow volume managers to support multipath hardware.
439
440config DM_MULTIPATH_QL
441 tristate "I/O Path Selector based on the number of in-flight I/Os"
442 depends on DM_MULTIPATH
443 help
444 This path selector is a dynamic load balancer which selects
445 the path with the least number of in-flight I/Os.
446
447 If unsure, say N.
448
449config DM_MULTIPATH_ST
450 tristate "I/O Path Selector based on the service time"
451 depends on DM_MULTIPATH
452 help
453 This path selector is a dynamic load balancer which selects
454 the path expected to complete the incoming I/O in the shortest
455 time.
456
457 If unsure, say N.
458
459config DM_MULTIPATH_HST
460 tristate "I/O Path Selector based on historical service time"
461 depends on DM_MULTIPATH
462 help
463 This path selector is a dynamic load balancer which selects
464 the path expected to complete the incoming I/O in the shortest
465 time by comparing estimated service time (based on historical
466 service time).
467
468 If unsure, say N.
469
470config DM_MULTIPATH_IOA
471 tristate "I/O Path Selector based on CPU submission"
472 depends on DM_MULTIPATH
473 help
474 This path selector selects the path based on the CPU the IO is
475 executed on and the CPU to path mapping setup at path addition time.
476
477 If unsure, say N.
478
479config DM_DELAY
480 tristate "I/O delaying target"
481 depends on BLK_DEV_DM
482 help
483 A target that delays reads and/or writes and can send
484 them to different devices. Useful for testing.
485
486 If unsure, say N.
487
488config DM_DUST
489 tristate "Bad sector simulation target"
490 depends on BLK_DEV_DM
491 help
492 A target that simulates bad sector behavior.
493 Useful for testing.
494
495 If unsure, say N.
496
497config DM_INIT
498 bool "DM \"dm-mod.create=\" parameter support"
499 depends on BLK_DEV_DM=y
500 help
501 Enable "dm-mod.create=" parameter to create mapped devices at init time.
502 This option is useful to allow mounting rootfs without requiring an
503 initramfs.
504 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..."
505 format.
506
507 If unsure, say N.
508
509config DM_UEVENT
510 bool "DM uevents"
511 depends on BLK_DEV_DM
512 help
513 Generate udev events for DM events.
514
515config DM_FLAKEY
516 tristate "Flakey target"
517 depends on BLK_DEV_DM
518 help
519 A target that intermittently fails I/O for debugging purposes.
520
521config DM_VERITY
522 tristate "Verity target support"
523 depends on BLK_DEV_DM
524 select CRYPTO
525 select CRYPTO_HASH
526 select DM_BUFIO
527 help
528 This device-mapper target creates a read-only device that
529 transparently validates the data on one underlying device against
530 a pre-generated tree of cryptographic checksums stored on a second
531 device.
532
533 You'll need to activate the digests you're going to use in the
534 cryptoapi configuration.
535
536 To compile this code as a module, choose M here: the module will
537 be called dm-verity.
538
539 If unsure, say N.
540
541config DM_VERITY_VERIFY_ROOTHASH_SIG
542 def_bool n
543 bool "Verity data device root hash signature verification support"
544 depends on DM_VERITY
545 select SYSTEM_DATA_VERIFICATION
546 help
547 Add ability for dm-verity device to be validated if the
548 pre-generated tree of cryptographic checksums passed has a pkcs#7
549 signature file that can validate the roothash of the tree.
550
551 By default, rely on the builtin trusted keyring.
552
553 If unsure, say N.
554
555config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
556 bool "Verity data device root hash signature verification with secondary keyring"
557 depends on DM_VERITY_VERIFY_ROOTHASH_SIG
558 depends on SECONDARY_TRUSTED_KEYRING
559 help
560 Rely on the secondary trusted keyring to verify dm-verity signatures.
561
562 If unsure, say N.
563
564config DM_VERITY_FEC
565 bool "Verity forward error correction support"
566 depends on DM_VERITY
567 select REED_SOLOMON
568 select REED_SOLOMON_DEC8
569 help
570 Add forward error correction support to dm-verity. This option
571 makes it possible to use pre-generated error correction data to
572 recover from corrupted blocks.
573
574 If unsure, say N.
575
576config DM_SWITCH
577 tristate "Switch target support (EXPERIMENTAL)"
578 depends on BLK_DEV_DM
579 help
580 This device-mapper target creates a device that supports an arbitrary
581 mapping of fixed-size regions of I/O across a fixed set of paths.
582 The path used for any specific region can be switched dynamically
583 by sending the target a message.
584
585 To compile this code as a module, choose M here: the module will
586 be called dm-switch.
587
588 If unsure, say N.
589
590config DM_LOG_WRITES
591 tristate "Log writes target support"
592 depends on BLK_DEV_DM
593 help
594 This device-mapper target takes two devices, one device to use
595 normally, one to log all write operations done to the first device.
596 This is for use by file system developers wishing to verify that
597 their fs is writing a consistent file system at all times by allowing
598 them to replay the log in a variety of ways and to check the
599 contents.
600
601 To compile this code as a module, choose M here: the module will
602 be called dm-log-writes.
603
604 If unsure, say N.
605
606config DM_INTEGRITY
607 tristate "Integrity target support"
608 depends on BLK_DEV_DM
609 select BLK_DEV_INTEGRITY
610 select DM_BUFIO
611 select CRYPTO
612 select CRYPTO_SKCIPHER
613 select ASYNC_XOR
614 select DM_AUDIT if AUDIT
615 help
616 This device-mapper target emulates a block device that has
617 additional per-sector tags that can be used for storing
618 integrity information.
619
620 This integrity target is used with the dm-crypt target to
621 provide authenticated disk encryption or it can be used
622 standalone.
623
624 To compile this code as a module, choose M here: the module will
625 be called dm-integrity.
626
627config DM_ZONED
628 tristate "Drive-managed zoned block device target support"
629 depends on BLK_DEV_DM
630 depends on BLK_DEV_ZONED
631 select CRC32
632 help
633 This device-mapper target takes a host-managed or host-aware zoned
634 block device and exposes most of its capacity as a regular block
635 device (drive-managed zoned block device) without any write
636 constraints. This is mainly intended for use with file systems that
637 do not natively support zoned block devices but still want to
638 benefit from the increased capacity offered by SMR disks. Other uses
639 by applications using raw block devices (for example object stores)
640 are also possible.
641
642 To compile this code as a module, choose M here: the module will
643 be called dm-zoned.
644
645 If unsure, say N.
646
647config DM_AUDIT
648 bool "DM audit events"
649 depends on AUDIT
650 help
651 Generate audit events for device-mapper.
652
653 Enables audit logging of several security relevant events in the
654 particular device-mapper targets, especially the integrity target.
655
656endif # MD
1#
2# Block device driver configuration
3#
4
5menuconfig 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
12if MD
13
14config 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
33config 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
47config 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
60config 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
80config 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
102config 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
121config 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
157config MULTICORE_RAID456
158 bool "RAID-4/RAID-5/RAID-6 Multicore processing (EXPERIMENTAL)"
159 depends on MD_RAID456
160 depends on SMP
161 depends on EXPERIMENTAL
162 ---help---
163 Enable the raid456 module to dispatch per-stripe raid operations to a
164 thread pool.
165
166 If unsure, say N.
167
168config MD_MULTIPATH
169 tristate "Multipath I/O support"
170 depends on BLK_DEV_MD
171 help
172 MD_MULTIPATH provides a simple multi-path personality for use
173 the MD framework. It is not under active development. New
174 projects should consider using DM_MULTIPATH which has more
175 features and more testing.
176
177 If unsure, say N.
178
179config MD_FAULTY
180 tristate "Faulty test module for MD"
181 depends on BLK_DEV_MD
182 help
183 The "faulty" module allows for a block device that occasionally returns
184 read or write errors. It is useful for testing.
185
186 In unsure, say N.
187
188config BLK_DEV_DM
189 tristate "Device mapper support"
190 ---help---
191 Device-mapper is a low level volume manager. It works by allowing
192 people to specify mappings for ranges of logical sectors. Various
193 mapping types are available, in addition people may write their own
194 modules containing custom mappings if they wish.
195
196 Higher level volume managers such as LVM2 use this driver.
197
198 To compile this as a module, choose M here: the module will be
199 called dm-mod.
200
201 If unsure, say N.
202
203config DM_DEBUG
204 boolean "Device mapper debugging support"
205 depends on BLK_DEV_DM
206 ---help---
207 Enable this for messages that may help debug device-mapper problems.
208
209 If unsure, say N.
210
211config DM_BUFIO
212 tristate
213 depends on BLK_DEV_DM && EXPERIMENTAL
214 ---help---
215 This interface allows you to do buffered I/O on a device and acts
216 as a cache, holding recently-read blocks in memory and performing
217 delayed writes.
218
219source "drivers/md/persistent-data/Kconfig"
220
221config DM_CRYPT
222 tristate "Crypt target support"
223 depends on BLK_DEV_DM
224 select CRYPTO
225 select CRYPTO_CBC
226 ---help---
227 This device-mapper target allows you to create a device that
228 transparently encrypts the data on it. You'll need to activate
229 the ciphers you're going to use in the cryptoapi configuration.
230
231 Information on how to use dm-crypt can be found on
232
233 <http://www.saout.de/misc/dm-crypt/>
234
235 To compile this code as a module, choose M here: the module will
236 be called dm-crypt.
237
238 If unsure, say N.
239
240config DM_SNAPSHOT
241 tristate "Snapshot target"
242 depends on BLK_DEV_DM
243 ---help---
244 Allow volume managers to take writable snapshots of a device.
245
246config DM_THIN_PROVISIONING
247 tristate "Thin provisioning target (EXPERIMENTAL)"
248 depends on BLK_DEV_DM && EXPERIMENTAL
249 select DM_PERSISTENT_DATA
250 ---help---
251 Provides thin provisioning and snapshots that share a data store.
252
253config DM_DEBUG_BLOCK_STACK_TRACING
254 boolean "Keep stack trace of thin provisioning block lock holders"
255 depends on STACKTRACE_SUPPORT && DM_THIN_PROVISIONING
256 select STACKTRACE
257 ---help---
258 Enable this for messages that may help debug problems with the
259 block manager locking used by thin provisioning.
260
261 If unsure, say N.
262
263config DM_DEBUG_SPACE_MAPS
264 boolean "Extra validation for thin provisioning space maps"
265 depends on DM_THIN_PROVISIONING
266 ---help---
267 Enable this for messages that may help debug problems with the
268 space maps used by thin provisioning.
269
270 If unsure, say N.
271
272config DM_MIRROR
273 tristate "Mirror target"
274 depends on BLK_DEV_DM
275 ---help---
276 Allow volume managers to mirror logical volumes, also
277 needed for live data migration tools such as 'pvmove'.
278
279config DM_RAID
280 tristate "RAID 1/4/5/6 target"
281 depends on BLK_DEV_DM
282 select MD_RAID1
283 select MD_RAID456
284 select BLK_DEV_MD
285 ---help---
286 A dm target that supports RAID1, RAID4, RAID5 and RAID6 mappings
287
288 A RAID-5 set of N drives with a capacity of C MB per drive provides
289 the capacity of C * (N - 1) MB, and protects against a failure
290 of a single drive. For a given sector (row) number, (N - 1) drives
291 contain data sectors, and one drive contains the parity protection.
292 For a RAID-4 set, the parity blocks are present on a single drive,
293 while a RAID-5 set distributes the parity across the drives in one
294 of the available parity distribution methods.
295
296 A RAID-6 set of N drives with a capacity of C MB per drive
297 provides the capacity of C * (N - 2) MB, and protects
298 against a failure of any two drives. For a given sector
299 (row) number, (N - 2) drives contain data sectors, and two
300 drives contains two independent redundancy syndromes. Like
301 RAID-5, RAID-6 distributes the syndromes across the drives
302 in one of the available parity distribution methods.
303
304config DM_LOG_USERSPACE
305 tristate "Mirror userspace logging (EXPERIMENTAL)"
306 depends on DM_MIRROR && EXPERIMENTAL && NET
307 select CONNECTOR
308 ---help---
309 The userspace logging module provides a mechanism for
310 relaying the dm-dirty-log API to userspace. Log designs
311 which are more suited to userspace implementation (e.g.
312 shared storage logs) or experimental logs can be implemented
313 by leveraging this framework.
314
315config DM_ZERO
316 tristate "Zero target"
317 depends on BLK_DEV_DM
318 ---help---
319 A target that discards writes, and returns all zeroes for
320 reads. Useful in some recovery situations.
321
322config DM_MULTIPATH
323 tristate "Multipath target"
324 depends on BLK_DEV_DM
325 # nasty syntax but means make DM_MULTIPATH independent
326 # of SCSI_DH if the latter isn't defined but if
327 # it is, DM_MULTIPATH must depend on it. We get a build
328 # error if SCSI_DH=m and DM_MULTIPATH=y
329 depends on SCSI_DH || !SCSI_DH
330 ---help---
331 Allow volume managers to support multipath hardware.
332
333config DM_MULTIPATH_QL
334 tristate "I/O Path Selector based on the number of in-flight I/Os"
335 depends on DM_MULTIPATH
336 ---help---
337 This path selector is a dynamic load balancer which selects
338 the path with the least number of in-flight I/Os.
339
340 If unsure, say N.
341
342config DM_MULTIPATH_ST
343 tristate "I/O Path Selector based on the service time"
344 depends on DM_MULTIPATH
345 ---help---
346 This path selector is a dynamic load balancer which selects
347 the path expected to complete the incoming I/O in the shortest
348 time.
349
350 If unsure, say N.
351
352config DM_DELAY
353 tristate "I/O delaying target (EXPERIMENTAL)"
354 depends on BLK_DEV_DM && EXPERIMENTAL
355 ---help---
356 A target that delays reads and/or writes and can send
357 them to different devices. Useful for testing.
358
359 If unsure, say N.
360
361config DM_UEVENT
362 bool "DM uevents"
363 depends on BLK_DEV_DM
364 ---help---
365 Generate udev events for DM events.
366
367config DM_FLAKEY
368 tristate "Flakey target (EXPERIMENTAL)"
369 depends on BLK_DEV_DM && EXPERIMENTAL
370 ---help---
371 A target that intermittently fails I/O for debugging purposes.
372
373config DM_VERITY
374 tristate "Verity target support (EXPERIMENTAL)"
375 depends on BLK_DEV_DM && EXPERIMENTAL
376 select CRYPTO
377 select CRYPTO_HASH
378 select DM_BUFIO
379 ---help---
380 This device-mapper target creates a read-only device that
381 transparently validates the data on one underlying device against
382 a pre-generated tree of cryptographic checksums stored on a second
383 device.
384
385 You'll need to activate the digests you're going to use in the
386 cryptoapi configuration.
387
388 To compile this code as a module, choose M here: the module will
389 be called dm-verity.
390
391 If unsure, say N.
392
393endif # MD