1 # SPDX-License-Identifier: GPL-2.0-only
3 # Block device driver configuration
7 bool "Multiple devices driver support (RAID and LVM)"
11 Support multiple physical spindles through a single logical device.
12 Required for RAID and logical volume management.
17 tristate "RAID support"
18 select BLOCK_HOLDER_DEPRECATED if SYSFS
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.
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.
37 bool "Autodetect RAID arrays during kernel boot"
38 depends on BLK_DEV_MD=y
41 If you say Y here, then the kernel will try to autodetect raid
42 arrays as part of its boot process.
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.
51 tristate "Linear (append) mode (deprecated)"
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.
58 To compile this as a module, choose M here: the module
59 will be called linear.
64 tristate "RAID-0 (striping) mode"
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.
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.
78 To compile this as a module, choose M here: the module
84 tristate "RAID-1 (mirroring) mode"
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)
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.
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.
106 tristate "RAID-10 (mirrored striping) mode"
107 depends on BLK_DEV_MD
109 RAID-10 provides a combination of striping (RAID-0) and
110 mirroring (RAID-1) with easier configuration and more flexible
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
115 RAID-10 provides a variety of layouts that provide different levels
116 of redundancy and performance.
118 RAID-10 requires mdadm-1.7.0 or later, available at:
120 https://www.kernel.org/pub/linux/utils/raid/mdadm/
125 tristate "RAID-4/RAID-5/RAID-6 mode"
126 depends on BLK_DEV_MD
132 select ASYNC_RAID6_RECOV
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.
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.
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.
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.
162 tristate "Multipath I/O support (deprecated)"
163 depends on BLK_DEV_MD
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.
173 tristate "Faulty test module for MD (deprecated)"
174 depends on BLK_DEV_MD
176 The "faulty" module allows for a block device that occasionally returns
177 read or write errors. It is useful for testing.
183 tristate "Cluster Support for MD"
184 depends on BLK_DEV_MD
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.
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
198 source "drivers/md/bcache/Kconfig"
200 config BLK_DEV_DM_BUILTIN
204 tristate "Device mapper support"
205 select BLOCK_HOLDER_DEPRECATED if SYSFS
206 select BLK_DEV_DM_BUILTIN
207 depends on DAX || DAX=n
209 Device-mapper is a low level volume manager. It works by allowing
210 people to specify mappings for ranges of logical sectors. Various
211 mapping types are available, in addition people may write their own
212 modules containing custom mappings if they wish.
214 Higher level volume managers such as LVM2 use this driver.
216 To compile this as a module, choose M here: the module will be
222 bool "Device mapper debugging support"
223 depends on BLK_DEV_DM
225 Enable this for messages that may help debug device-mapper problems.
231 depends on BLK_DEV_DM
233 This interface allows you to do buffered I/O on a device and acts
234 as a cache, holding recently-read blocks in memory and performing
237 config DM_DEBUG_BLOCK_MANAGER_LOCKING
238 bool "Block manager locking"
241 Block manager locking can catch various metadata corruption issues.
245 config DM_DEBUG_BLOCK_STACK_TRACING
246 bool "Keep stack trace of persistent data block lock holders"
247 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
250 Enable this for messages that may help debug problems with the
251 block manager locking used by thin provisioning and caching.
257 depends on BLK_DEV_DM
259 Some bio locking schemes used by other device-mapper targets
260 including thin provisioning.
262 source "drivers/md/persistent-data/Kconfig"
265 tristate "Unstriped target"
266 depends on BLK_DEV_DM
268 Unstripes I/O so it is issued solely on a single drive in a HW
269 RAID0 or dm-striped target.
272 tristate "Crypt target support"
273 depends on BLK_DEV_DM
274 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n)
275 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n)
280 This device-mapper target allows you to create a device that
281 transparently encrypts the data on it. You'll need to activate
282 the ciphers you're going to use in the cryptoapi configuration.
284 For further information on dm-crypt and userspace tools see:
285 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
287 To compile this code as a module, choose M here: the module will
293 tristate "Snapshot target"
294 depends on BLK_DEV_DM
297 Allow volume managers to take writable snapshots of a device.
299 config DM_THIN_PROVISIONING
300 tristate "Thin provisioning target"
301 depends on BLK_DEV_DM
302 select DM_PERSISTENT_DATA
305 Provides thin provisioning and snapshots that share a data store.
308 tristate "Cache target (EXPERIMENTAL)"
309 depends on BLK_DEV_DM
311 select DM_PERSISTENT_DATA
314 dm-cache attempts to improve performance of a block device by
315 moving frequently used data to a smaller, higher performance
316 device. Different 'policy' plugins can be used to change the
317 algorithms used to select which blocks are promoted, demoted,
318 cleaned etc. It supports writeback and writethrough modes.
321 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
325 A cache policy that uses a multiqueue ordered by recent hits
326 to select which blocks should be promoted and demoted.
327 This is meant to be a general purpose policy. It prioritises
328 reads over writes. This SMQ policy (vs MQ) offers the promise
329 of less memory utilization, improved performance and increased
330 adaptability in the face of changing workloads.
333 tristate "Writecache target"
334 depends on BLK_DEV_DM
336 The writecache target caches writes on persistent memory or SSD.
337 It is intended for databases or other programs that need extremely
340 The writecache target doesn't cache reads because reads are supposed
341 to be cached in standard RAM.
344 tristate "Emulated block size target (EXPERIMENTAL)"
345 depends on BLK_DEV_DM && !HIGHMEM
348 dm-ebs emulates smaller logical block size on backing devices
349 with larger ones (e.g. 512 byte sectors on 4K native disks).
352 tristate "Era target (EXPERIMENTAL)"
353 depends on BLK_DEV_DM
355 select DM_PERSISTENT_DATA
358 dm-era tracks which parts of a block device are written to
359 over time. Useful for maintaining cache coherency when using
363 tristate "Clone target (EXPERIMENTAL)"
364 depends on BLK_DEV_DM
366 select DM_PERSISTENT_DATA
368 dm-clone produces a one-to-one copy of an existing, read-only source
369 device into a writable destination device. The cloned device is
370 visible/mountable immediately and the copy of the source device to the
371 destination device happens in the background, in parallel with user
377 tristate "Mirror target"
378 depends on BLK_DEV_DM
380 Allow volume managers to mirror logical volumes, also
381 needed for live data migration tools such as 'pvmove'.
383 config DM_LOG_USERSPACE
384 tristate "Mirror userspace logging"
385 depends on DM_MIRROR && NET
388 The userspace logging module provides a mechanism for
389 relaying the dm-dirty-log API to userspace. Log designs
390 which are more suited to userspace implementation (e.g.
391 shared storage logs) or experimental logs can be implemented
392 by leveraging this framework.
395 tristate "RAID 1/4/5/6/10 target"
396 depends on BLK_DEV_DM
403 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
405 A RAID-5 set of N drives with a capacity of C MB per drive provides
406 the capacity of C * (N - 1) MB, and protects against a failure
407 of a single drive. For a given sector (row) number, (N - 1) drives
408 contain data sectors, and one drive contains the parity protection.
409 For a RAID-4 set, the parity blocks are present on a single drive,
410 while a RAID-5 set distributes the parity across the drives in one
411 of the available parity distribution methods.
413 A RAID-6 set of N drives with a capacity of C MB per drive
414 provides the capacity of C * (N - 2) MB, and protects
415 against a failure of any two drives. For a given sector
416 (row) number, (N - 2) drives contain data sectors, and two
417 drives contains two independent redundancy syndromes. Like
418 RAID-5, RAID-6 distributes the syndromes across the drives
419 in one of the available parity distribution methods.
422 tristate "Zero target"
423 depends on BLK_DEV_DM
425 A target that discards writes, and returns all zeroes for
426 reads. Useful in some recovery situations.
429 tristate "Multipath target"
430 depends on BLK_DEV_DM
431 # nasty syntax but means make DM_MULTIPATH independent
432 # of SCSI_DH if the latter isn't defined but if
433 # it is, DM_MULTIPATH must depend on it. We get a build
434 # error if SCSI_DH=m and DM_MULTIPATH=y
435 depends on !SCSI_DH || SCSI
437 Allow volume managers to support multipath hardware.
439 config DM_MULTIPATH_QL
440 tristate "I/O Path Selector based on the number of in-flight I/Os"
441 depends on DM_MULTIPATH
443 This path selector is a dynamic load balancer which selects
444 the path with the least number of in-flight I/Os.
448 config DM_MULTIPATH_ST
449 tristate "I/O Path Selector based on the service time"
450 depends on DM_MULTIPATH
452 This path selector is a dynamic load balancer which selects
453 the path expected to complete the incoming I/O in the shortest
458 config DM_MULTIPATH_HST
459 tristate "I/O Path Selector based on historical service time"
460 depends on DM_MULTIPATH
462 This path selector is a dynamic load balancer which selects
463 the path expected to complete the incoming I/O in the shortest
464 time by comparing estimated service time (based on historical
469 config DM_MULTIPATH_IOA
470 tristate "I/O Path Selector based on CPU submission"
471 depends on DM_MULTIPATH
473 This path selector selects the path based on the CPU the IO is
474 executed on and the CPU to path mapping setup at path addition time.
479 tristate "I/O delaying target"
480 depends on BLK_DEV_DM
482 A target that delays reads and/or writes and can send
483 them to different devices. Useful for testing.
488 tristate "Bad sector simulation target"
489 depends on BLK_DEV_DM
491 A target that simulates bad sector behavior.
497 bool "DM \"dm-mod.create=\" parameter support"
498 depends on BLK_DEV_DM=y
500 Enable "dm-mod.create=" parameter to create mapped devices at init time.
501 This option is useful to allow mounting rootfs without requiring an
503 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..."
510 depends on BLK_DEV_DM
512 Generate udev events for DM events.
515 tristate "Flakey target"
516 depends on BLK_DEV_DM
518 A target that intermittently fails I/O for debugging purposes.
521 tristate "BOW support"
522 depends on BLK_DEV_DM
527 This device-mapper target creates a read-only device that
528 transparently validates the data on one underlying device against
529 a pre-generated tree of cryptographic checksums stored on a second
532 You'll need to activate the digests you're going to use in the
533 cryptoapi configuration.
535 To compile this code as a module, choose M here: the module will
541 tristate "Verity target support"
542 depends on BLK_DEV_DM
547 This device-mapper target creates a read-only device that
548 transparently validates the data on one underlying device against
549 a pre-generated tree of cryptographic checksums stored on a second
552 You'll need to activate the digests you're going to use in the
553 cryptoapi configuration.
555 To compile this code as a module, choose M here: the module will
560 config DM_VERITY_VERIFY_ROOTHASH_SIG
562 bool "Verity data device root hash signature verification support"
564 select SYSTEM_DATA_VERIFICATION
566 Add ability for dm-verity device to be validated if the
567 pre-generated tree of cryptographic checksums passed has a pkcs#7
568 signature file that can validate the roothash of the tree.
570 By default, rely on the builtin trusted keyring.
574 config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
575 bool "Verity data device root hash signature verification with secondary keyring"
576 depends on DM_VERITY_VERIFY_ROOTHASH_SIG
577 depends on SECONDARY_TRUSTED_KEYRING
579 Rely on the secondary trusted keyring to verify dm-verity signatures.
584 bool "Verity forward error correction support"
587 select REED_SOLOMON_DEC8
589 Add forward error correction support to dm-verity. This option
590 makes it possible to use pre-generated error correction data to
591 recover from corrupted blocks.
596 tristate "Switch target support (EXPERIMENTAL)"
597 depends on BLK_DEV_DM
599 This device-mapper target creates a device that supports an arbitrary
600 mapping of fixed-size regions of I/O across a fixed set of paths.
601 The path used for any specific region can be switched dynamically
602 by sending the target a message.
604 To compile this code as a module, choose M here: the module will
610 tristate "Log writes target support"
611 depends on BLK_DEV_DM
613 This device-mapper target takes two devices, one device to use
614 normally, one to log all write operations done to the first device.
615 This is for use by file system developers wishing to verify that
616 their fs is writing a consistent file system at all times by allowing
617 them to replay the log in a variety of ways and to check the
620 To compile this code as a module, choose M here: the module will
621 be called dm-log-writes.
626 tristate "Integrity target support"
627 depends on BLK_DEV_DM
628 select BLK_DEV_INTEGRITY
631 select CRYPTO_SKCIPHER
634 This device-mapper target emulates a block device that has
635 additional per-sector tags that can be used for storing
636 integrity information.
638 This integrity target is used with the dm-crypt target to
639 provide authenticated disk encryption or it can be used
642 To compile this code as a module, choose M here: the module will
643 be called dm-integrity.
646 tristate "Drive-managed zoned block device target support"
647 depends on BLK_DEV_DM
648 depends on BLK_DEV_ZONED
651 This device-mapper target takes a host-managed or host-aware zoned
652 block device and exposes most of its capacity as a regular block
653 device (drive-managed zoned block device) without any write
654 constraints. This is mainly intended for use with file systems that
655 do not natively support zoned block devices but still want to
656 benefit from the increased capacity offered by SMR disks. Other uses
657 by applications using raw block devices (for example object stores)
660 To compile this code as a module, choose M here: the module will