1 # SPDX-License-Identifier: GPL-2.0-only
3 # Block device driver configuration
7 bool "Multiple devices driver support (RAID and LVM)"
10 Support multiple physical spindles through a single logical device.
11 Required for RAID and logical volume management.
16 tristate "RAID support"
17 select BLOCK_HOLDER_DEPRECATED if SYSFS
18 # BLOCK_LEGACY_AUTOLOAD requirement should be removed
19 # after relevant mdadm enhancements - to make "names=yes"
20 # the default - are widely available.
21 select BLOCK_LEGACY_AUTOLOAD
23 This driver lets you combine several hard disk partitions into one
24 logical block device. This can be used to simply append one
25 partition to another one or to combine several redundant hard disks
26 into a RAID1/4/5 device so as to provide protection against hard
27 disk failures. This is called "Software RAID" since the combining of
28 the partitions is done by the kernel. "Hardware RAID" means that the
29 combining is done by a dedicated controller; if you have such a
30 controller, you do not need to say Y here.
32 More information about Software RAID on Linux is contained in the
33 Software RAID mini-HOWTO, available from
34 <https://www.tldp.org/docs.html#howto>. There you will also learn
35 where to get the supporting user space utilities raidtools.
40 bool "Autodetect RAID arrays during kernel boot"
41 depends on BLK_DEV_MD=y
44 If you say Y here, then the kernel will try to autodetect raid
45 arrays as part of its boot process.
47 If you don't use raid and say Y, this autodetection can cause
48 a several-second delay in the boot time due to various
49 synchronisation steps that are part of this step.
54 tristate "Linear (append) mode (deprecated)"
57 If you say Y here, then your multiple devices driver will be able to
58 use the so-called linear mode, i.e. it will combine the hard disk
59 partitions by simply appending one to the other.
61 To compile this as a module, choose M here: the module
62 will be called linear.
67 tristate "RAID-0 (striping) mode"
70 If you say Y here, then your multiple devices driver will be able to
71 use the so-called raid0 mode, i.e. it will combine the hard disk
72 partitions into one logical device in such a fashion as to fill them
73 up evenly, one chunk here and one chunk there. This will increase
74 the throughput rate if the partitions reside on distinct disks.
76 Information about Software RAID on Linux is contained in the
77 Software-RAID mini-HOWTO, available from
78 <https://www.tldp.org/docs.html#howto>. There you will also
79 learn where to get the supporting user space utilities raidtools.
81 To compile this as a module, choose M here: the module
87 tristate "RAID-1 (mirroring) mode"
90 A RAID-1 set consists of several disk drives which are exact copies
91 of each other. In the event of a mirror failure, the RAID driver
92 will continue to use the operational mirrors in the set, providing
93 an error free MD (multiple device) to the higher levels of the
94 kernel. In a set with N drives, the available space is the capacity
95 of a single drive, and the set protects against a failure of (N - 1)
98 Information about Software RAID on Linux is contained in the
99 Software-RAID mini-HOWTO, available from
100 <https://www.tldp.org/docs.html#howto>. There you will also
101 learn where to get the supporting user space utilities raidtools.
103 If you want to use such a RAID-1 set, say Y. To compile this code
104 as a module, choose M here: the module will be called raid1.
109 tristate "RAID-10 (mirrored striping) mode"
110 depends on BLK_DEV_MD
112 RAID-10 provides a combination of striping (RAID-0) and
113 mirroring (RAID-1) with easier configuration and more flexible
115 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
116 be the same size (or at least, only as much as the smallest device
118 RAID-10 provides a variety of layouts that provide different levels
119 of redundancy and performance.
121 RAID-10 requires mdadm-1.7.0 or later, available at:
123 https://www.kernel.org/pub/linux/utils/raid/mdadm/
128 tristate "RAID-4/RAID-5/RAID-6 mode"
129 depends on BLK_DEV_MD
135 select ASYNC_RAID6_RECOV
137 A RAID-5 set of N drives with a capacity of C MB per drive provides
138 the capacity of C * (N - 1) MB, and protects against a failure
139 of a single drive. For a given sector (row) number, (N - 1) drives
140 contain data sectors, and one drive contains the parity protection.
141 For a RAID-4 set, the parity blocks are present on a single drive,
142 while a RAID-5 set distributes the parity across the drives in one
143 of the available parity distribution methods.
145 A RAID-6 set of N drives with a capacity of C MB per drive
146 provides the capacity of C * (N - 2) MB, and protects
147 against a failure of any two drives. For a given sector
148 (row) number, (N - 2) drives contain data sectors, and two
149 drives contains two independent redundancy syndromes. Like
150 RAID-5, RAID-6 distributes the syndromes across the drives
151 in one of the available parity distribution methods.
153 Information about Software RAID on Linux is contained in the
154 Software-RAID mini-HOWTO, available from
155 <https://www.tldp.org/docs.html#howto>. There you will also
156 learn where to get the supporting user space utilities raidtools.
158 If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To
159 compile this code as a module, choose M here: the module
160 will be called raid456.
165 tristate "Multipath I/O support (deprecated)"
166 depends on BLK_DEV_MD
168 MD_MULTIPATH provides a simple multi-path personality for use
169 the MD framework. It is not under active development. New
170 projects should consider using DM_MULTIPATH which has more
171 features and more testing.
176 tristate "Faulty test module for MD (deprecated)"
177 depends on BLK_DEV_MD
179 The "faulty" module allows for a block device that occasionally returns
180 read or write errors. It is useful for testing.
186 tristate "Cluster Support for MD"
187 depends on BLK_DEV_MD
191 Clustering support for MD devices. This enables locking and
192 synchronization across multiple systems on the cluster, so all
193 nodes in the cluster can access the MD devices simultaneously.
195 This brings the redundancy (and uptime) of RAID levels across the
196 nodes of the cluster. Currently, it can work with raid1 and raid10
201 source "drivers/md/bcache/Kconfig"
203 config BLK_DEV_DM_BUILTIN
207 tristate "Device mapper support"
208 select BLOCK_HOLDER_DEPRECATED if SYSFS
209 select BLK_DEV_DM_BUILTIN
210 select BLK_MQ_STACKING
211 depends on DAX || DAX=n
213 Device-mapper is a low level volume manager. It works by allowing
214 people to specify mappings for ranges of logical sectors. Various
215 mapping types are available, in addition people may write their own
216 modules containing custom mappings if they wish.
218 Higher level volume managers such as LVM2 use this driver.
220 To compile this as a module, choose M here: the module will be
226 bool "Device mapper debugging support"
227 depends on BLK_DEV_DM
229 Enable this for messages that may help debug device-mapper problems.
235 depends on BLK_DEV_DM
237 This interface allows you to do buffered I/O on a device and acts
238 as a cache, holding recently-read blocks in memory and performing
241 config DM_DEBUG_BLOCK_MANAGER_LOCKING
242 bool "Block manager locking"
245 Block manager locking can catch various metadata corruption issues.
249 config DM_DEBUG_BLOCK_STACK_TRACING
250 bool "Keep stack trace of persistent data block lock holders"
251 depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
254 Enable this for messages that may help debug problems with the
255 block manager locking used by thin provisioning and caching.
261 depends on BLK_DEV_DM
263 Some bio locking schemes used by other device-mapper targets
264 including thin provisioning.
266 source "drivers/md/persistent-data/Kconfig"
269 tristate "Unstriped target"
270 depends on BLK_DEV_DM
272 Unstripes I/O so it is issued solely on a single drive in a HW
273 RAID0 or dm-striped target.
276 tristate "Crypt target support"
277 depends on BLK_DEV_DM
278 depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n)
279 depends on (TRUSTED_KEYS || TRUSTED_KEYS=n)
284 This device-mapper target allows you to create a device that
285 transparently encrypts the data on it. You'll need to activate
286 the ciphers you're going to use in the cryptoapi configuration.
288 For further information on dm-crypt and userspace tools see:
289 <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
291 To compile this code as a module, choose M here: the module will
297 tristate "Snapshot target"
298 depends on BLK_DEV_DM
301 Allow volume managers to take writable snapshots of a device.
303 config DM_THIN_PROVISIONING
304 tristate "Thin provisioning target"
305 depends on BLK_DEV_DM
306 select DM_PERSISTENT_DATA
309 Provides thin provisioning and snapshots that share a data store.
312 tristate "Cache target (EXPERIMENTAL)"
313 depends on BLK_DEV_DM
315 select DM_PERSISTENT_DATA
318 dm-cache attempts to improve performance of a block device by
319 moving frequently used data to a smaller, higher performance
320 device. Different 'policy' plugins can be used to change the
321 algorithms used to select which blocks are promoted, demoted,
322 cleaned etc. It supports writeback and writethrough modes.
325 tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
329 A cache policy that uses a multiqueue ordered by recent hits
330 to select which blocks should be promoted and demoted.
331 This is meant to be a general purpose policy. It prioritises
332 reads over writes. This SMQ policy (vs MQ) offers the promise
333 of less memory utilization, improved performance and increased
334 adaptability in the face of changing workloads.
337 tristate "Writecache target"
338 depends on BLK_DEV_DM
340 The writecache target caches writes on persistent memory or SSD.
341 It is intended for databases or other programs that need extremely
344 The writecache target doesn't cache reads because reads are supposed
345 to be cached in standard RAM.
348 tristate "Emulated block size target (EXPERIMENTAL)"
349 depends on BLK_DEV_DM && !HIGHMEM
352 dm-ebs emulates smaller logical block size on backing devices
353 with larger ones (e.g. 512 byte sectors on 4K native disks).
356 tristate "Era target (EXPERIMENTAL)"
357 depends on BLK_DEV_DM
359 select DM_PERSISTENT_DATA
362 dm-era tracks which parts of a block device are written to
363 over time. Useful for maintaining cache coherency when using
367 tristate "Clone target (EXPERIMENTAL)"
368 depends on BLK_DEV_DM
370 select DM_PERSISTENT_DATA
372 dm-clone produces a one-to-one copy of an existing, read-only source
373 device into a writable destination device. The cloned device is
374 visible/mountable immediately and the copy of the source device to the
375 destination device happens in the background, in parallel with user
381 tristate "Mirror target"
382 depends on BLK_DEV_DM
384 Allow volume managers to mirror logical volumes, also
385 needed for live data migration tools such as 'pvmove'.
387 config DM_LOG_USERSPACE
388 tristate "Mirror userspace logging"
389 depends on DM_MIRROR && NET
392 The userspace logging module provides a mechanism for
393 relaying the dm-dirty-log API to userspace. Log designs
394 which are more suited to userspace implementation (e.g.
395 shared storage logs) or experimental logs can be implemented
396 by leveraging this framework.
399 tristate "RAID 1/4/5/6/10 target"
400 depends on BLK_DEV_DM
407 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
409 A RAID-5 set of N drives with a capacity of C MB per drive provides
410 the capacity of C * (N - 1) MB, and protects against a failure
411 of a single drive. For a given sector (row) number, (N - 1) drives
412 contain data sectors, and one drive contains the parity protection.
413 For a RAID-4 set, the parity blocks are present on a single drive,
414 while a RAID-5 set distributes the parity across the drives in one
415 of the available parity distribution methods.
417 A RAID-6 set of N drives with a capacity of C MB per drive
418 provides the capacity of C * (N - 2) MB, and protects
419 against a failure of any two drives. For a given sector
420 (row) number, (N - 2) drives contain data sectors, and two
421 drives contains two independent redundancy syndromes. Like
422 RAID-5, RAID-6 distributes the syndromes across the drives
423 in one of the available parity distribution methods.
426 tristate "Zero target"
427 depends on BLK_DEV_DM
429 A target that discards writes, and returns all zeroes for
430 reads. Useful in some recovery situations.
433 tristate "Multipath target"
434 depends on BLK_DEV_DM
435 # nasty syntax but means make DM_MULTIPATH independent
436 # of SCSI_DH if the latter isn't defined but if
437 # it is, DM_MULTIPATH must depend on it. We get a build
438 # error if SCSI_DH=m and DM_MULTIPATH=y
439 depends on !SCSI_DH || SCSI
441 Allow volume managers to support multipath hardware.
443 config DM_MULTIPATH_QL
444 tristate "I/O Path Selector based on the number of in-flight I/Os"
445 depends on DM_MULTIPATH
447 This path selector is a dynamic load balancer which selects
448 the path with the least number of in-flight I/Os.
452 config DM_MULTIPATH_ST
453 tristate "I/O Path Selector based on the service time"
454 depends on DM_MULTIPATH
456 This path selector is a dynamic load balancer which selects
457 the path expected to complete the incoming I/O in the shortest
462 config DM_MULTIPATH_HST
463 tristate "I/O Path Selector based on historical service time"
464 depends on DM_MULTIPATH
466 This path selector is a dynamic load balancer which selects
467 the path expected to complete the incoming I/O in the shortest
468 time by comparing estimated service time (based on historical
473 config DM_MULTIPATH_IOA
474 tristate "I/O Path Selector based on CPU submission"
475 depends on DM_MULTIPATH
477 This path selector selects the path based on the CPU the IO is
478 executed on and the CPU to path mapping setup at path addition time.
483 tristate "I/O delaying target"
484 depends on BLK_DEV_DM
486 A target that delays reads and/or writes and can send
487 them to different devices. Useful for testing.
492 tristate "Bad sector simulation target"
493 depends on BLK_DEV_DM
495 A target that simulates bad sector behavior.
501 bool "DM \"dm-mod.create=\" parameter support"
502 depends on BLK_DEV_DM=y
504 Enable "dm-mod.create=" parameter to create mapped devices at init time.
505 This option is useful to allow mounting rootfs without requiring an
507 See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..."
514 depends on BLK_DEV_DM
516 Generate udev events for DM events.
519 tristate "Flakey target"
520 depends on BLK_DEV_DM
522 A target that intermittently fails I/O for debugging purposes.
525 tristate "Verity target support"
526 depends on BLK_DEV_DM
531 This device-mapper target creates a read-only device that
532 transparently validates the data on one underlying device against
533 a pre-generated tree of cryptographic checksums stored on a second
536 You'll need to activate the digests you're going to use in the
537 cryptoapi configuration.
539 To compile this code as a module, choose M here: the module will
544 config DM_VERITY_VERIFY_ROOTHASH_SIG
546 bool "Verity data device root hash signature verification support"
548 select SYSTEM_DATA_VERIFICATION
550 Add ability for dm-verity device to be validated if the
551 pre-generated tree of cryptographic checksums passed has a pkcs#7
552 signature file that can validate the roothash of the tree.
554 By default, rely on the builtin trusted keyring.
558 config DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
559 bool "Verity data device root hash signature verification with secondary keyring"
560 depends on DM_VERITY_VERIFY_ROOTHASH_SIG
561 depends on SECONDARY_TRUSTED_KEYRING
563 Rely on the secondary trusted keyring to verify dm-verity signatures.
568 bool "Verity forward error correction support"
571 select REED_SOLOMON_DEC8
573 Add forward error correction support to dm-verity. This option
574 makes it possible to use pre-generated error correction data to
575 recover from corrupted blocks.
580 tristate "Switch target support (EXPERIMENTAL)"
581 depends on BLK_DEV_DM
583 This device-mapper target creates a device that supports an arbitrary
584 mapping of fixed-size regions of I/O across a fixed set of paths.
585 The path used for any specific region can be switched dynamically
586 by sending the target a message.
588 To compile this code as a module, choose M here: the module will
594 tristate "Log writes target support"
595 depends on BLK_DEV_DM
597 This device-mapper target takes two devices, one device to use
598 normally, one to log all write operations done to the first device.
599 This is for use by file system developers wishing to verify that
600 their fs is writing a consistent file system at all times by allowing
601 them to replay the log in a variety of ways and to check the
604 To compile this code as a module, choose M here: the module will
605 be called dm-log-writes.
610 tristate "Integrity target support"
611 depends on BLK_DEV_DM
612 select BLK_DEV_INTEGRITY
615 select CRYPTO_SKCIPHER
617 select DM_AUDIT if AUDIT
619 This device-mapper target emulates a block device that has
620 additional per-sector tags that can be used for storing
621 integrity information.
623 This integrity target is used with the dm-crypt target to
624 provide authenticated disk encryption or it can be used
627 To compile this code as a module, choose M here: the module will
628 be called dm-integrity.
631 tristate "Drive-managed zoned block device target support"
632 depends on BLK_DEV_DM
633 depends on BLK_DEV_ZONED
636 This device-mapper target takes a host-managed or host-aware zoned
637 block device and exposes most of its capacity as a regular block
638 device (drive-managed zoned block device) without any write
639 constraints. This is mainly intended for use with file systems that
640 do not natively support zoned block devices but still want to
641 benefit from the increased capacity offered by SMR disks. Other uses
642 by applications using raw block devices (for example object stores)
645 To compile this code as a module, choose M here: the module will
651 bool "DM audit events"
654 Generate audit events for device-mapper.
656 Enables audit logging of several security relevant events in the
657 particular device-mapper targets, especially the integrity target.