xref: /openbmc/linux/drivers/md/Kconfig (revision f5005f78)
1#
2# Block device driver configuration
3#
4
5menuconfig MD
6	bool "Multiple devices driver support (RAID and LVM)"
7	depends on BLOCK
8	select SRCU
9	help
10	  Support multiple physical spindles through a single logical device.
11	  Required for RAID and logical volume management.
12
13if MD
14
15config BLK_DEV_MD
16	tristate "RAID support"
17	---help---
18	  This driver lets you combine several hard disk partitions into one
19	  logical block device. This can be used to simply append one
20	  partition to another one or to combine several redundant hard disks
21	  into a RAID1/4/5 device so as to provide protection against hard
22	  disk failures. This is called "Software RAID" since the combining of
23	  the partitions is done by the kernel. "Hardware RAID" means that the
24	  combining is done by a dedicated controller; if you have such a
25	  controller, you do not need to say Y here.
26
27	  More information about Software RAID on Linux is contained in the
28	  Software RAID mini-HOWTO, available from
29	  <http://www.tldp.org/docs.html#howto>. There you will also learn
30	  where to get the supporting user space utilities raidtools.
31
32	  If unsure, say N.
33
34config MD_AUTODETECT
35	bool "Autodetect RAID arrays during kernel boot"
36	depends on BLK_DEV_MD=y
37	default y
38	---help---
39	  If you say Y here, then the kernel will try to autodetect raid
40	  arrays as part of its boot process.
41
42	  If you don't use raid and say Y, this autodetection can cause
43	  a several-second delay in the boot time due to various
44	  synchronisation steps that are part of this step.
45
46	  If unsure, say Y.
47
48config MD_LINEAR
49	tristate "Linear (append) mode"
50	depends on BLK_DEV_MD
51	---help---
52	  If you say Y here, then your multiple devices driver will be able to
53	  use the so-called linear mode, i.e. it will combine the hard disk
54	  partitions by simply appending one to the other.
55
56	  To compile this as a module, choose M here: the module
57	  will be called linear.
58
59	  If unsure, say Y.
60
61config MD_RAID0
62	tristate "RAID-0 (striping) mode"
63	depends on BLK_DEV_MD
64	---help---
65	  If you say Y here, then your multiple devices driver will be able to
66	  use the so-called raid0 mode, i.e. it will combine the hard disk
67	  partitions into one logical device in such a fashion as to fill them
68	  up evenly, one chunk here and one chunk there. This will increase
69	  the throughput rate if the partitions reside on distinct disks.
70
71	  Information about Software RAID on Linux is contained in the
72	  Software-RAID mini-HOWTO, available from
73	  <http://www.tldp.org/docs.html#howto>. There you will also
74	  learn where to get the supporting user space utilities raidtools.
75
76	  To compile this as a module, choose M here: the module
77	  will be called raid0.
78
79	  If unsure, say Y.
80
81config MD_RAID1
82	tristate "RAID-1 (mirroring) mode"
83	depends on BLK_DEV_MD
84	---help---
85	  A RAID-1 set consists of several disk drives which are exact copies
86	  of each other.  In the event of a mirror failure, the RAID driver
87	  will continue to use the operational mirrors in the set, providing
88	  an error free MD (multiple device) to the higher levels of the
89	  kernel.  In a set with N drives, the available space is the capacity
90	  of a single drive, and the set protects against a failure of (N - 1)
91	  drives.
92
93	  Information about Software RAID on Linux is contained in the
94	  Software-RAID mini-HOWTO, available from
95	  <http://www.tldp.org/docs.html#howto>.  There you will also
96	  learn where to get the supporting user space utilities raidtools.
97
98	  If you want to use such a RAID-1 set, say Y.  To compile this code
99	  as a module, choose M here: the module will be called raid1.
100
101	  If unsure, say Y.
102
103config MD_RAID10
104	tristate "RAID-10 (mirrored striping) mode"
105	depends on BLK_DEV_MD
106	---help---
107	  RAID-10 provides a combination of striping (RAID-0) and
108	  mirroring (RAID-1) with easier configuration and more flexible
109	  layout.
110	  Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to
111	  be the same size (or at least, only as much as the smallest device
112	  will be used).
113	  RAID-10 provides a variety of layouts that provide different levels
114	  of redundancy and performance.
115
116	  RAID-10 requires mdadm-1.7.0 or later, available at:
117
118	  ftp://ftp.kernel.org/pub/linux/utils/raid/mdadm/
119
120	  If unsure, say Y.
121
122config MD_RAID456
123	tristate "RAID-4/RAID-5/RAID-6 mode"
124	depends on BLK_DEV_MD
125	select RAID6_PQ
126	select ASYNC_MEMCPY
127	select ASYNC_XOR
128	select ASYNC_PQ
129	select ASYNC_RAID6_RECOV
130	---help---
131	  A RAID-5 set of N drives with a capacity of C MB per drive provides
132	  the capacity of C * (N - 1) MB, and protects against a failure
133	  of a single drive. For a given sector (row) number, (N - 1) drives
134	  contain data sectors, and one drive contains the parity protection.
135	  For a RAID-4 set, the parity blocks are present on a single drive,
136	  while a RAID-5 set distributes the parity across the drives in one
137	  of the available parity distribution methods.
138
139	  A RAID-6 set of N drives with a capacity of C MB per drive
140	  provides the capacity of C * (N - 2) MB, and protects
141	  against a failure of any two drives. For a given sector
142	  (row) number, (N - 2) drives contain data sectors, and two
143	  drives contains two independent redundancy syndromes.  Like
144	  RAID-5, RAID-6 distributes the syndromes across the drives
145	  in one of the available parity distribution methods.
146
147	  Information about Software RAID on Linux is contained in the
148	  Software-RAID mini-HOWTO, available from
149	  <http://www.tldp.org/docs.html#howto>. There you will also
150	  learn where to get the supporting user space utilities raidtools.
151
152	  If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y.  To
153	  compile this code as a module, choose M here: the module
154	  will be called raid456.
155
156	  If unsure, say Y.
157
158config MD_MULTIPATH
159	tristate "Multipath I/O support"
160	depends on BLK_DEV_MD
161	help
162	  MD_MULTIPATH provides a simple multi-path personality for use
163	  the MD framework.  It is not under active development.  New
164	  projects should consider using DM_MULTIPATH which has more
165	  features and more testing.
166
167	  If unsure, say N.
168
169config MD_FAULTY
170	tristate "Faulty test module for MD"
171	depends on BLK_DEV_MD
172	help
173	  The "faulty" module allows for a block device that occasionally returns
174	  read or write errors.  It is useful for testing.
175
176	  In unsure, say N.
177
178
179config MD_CLUSTER
180	tristate "Cluster Support for MD (EXPERIMENTAL)"
181	depends on BLK_DEV_MD
182	depends on DLM
183	default n
184	---help---
185	Clustering support for MD devices. This enables locking and
186	synchronization across multiple systems on the cluster, so all
187	nodes in the cluster can access the MD devices simultaneously.
188
189	This brings the redundancy (and uptime) of RAID levels across the
190	nodes of the cluster.
191
192	If unsure, say N.
193
194source "drivers/md/bcache/Kconfig"
195
196config BLK_DEV_DM_BUILTIN
197	bool
198
199config BLK_DEV_DM
200	tristate "Device mapper support"
201	select BLK_DEV_DM_BUILTIN
202	---help---
203	  Device-mapper is a low level volume manager.  It works by allowing
204	  people to specify mappings for ranges of logical sectors.  Various
205	  mapping types are available, in addition people may write their own
206	  modules containing custom mappings if they wish.
207
208	  Higher level volume managers such as LVM2 use this driver.
209
210	  To compile this as a module, choose M here: the module will be
211	  called dm-mod.
212
213	  If unsure, say N.
214
215config DM_MQ_DEFAULT
216	bool "request-based DM: use blk-mq I/O path by default"
217	depends on BLK_DEV_DM
218	---help---
219	  This option enables the blk-mq based I/O path for request-based
220	  DM devices by default.  With the option the dm_mod.use_blk_mq
221	  module/boot option defaults to Y, without it to N, but it can
222	  still be overriden either way.
223
224	  If unsure say N.
225
226config DM_DEBUG
227	bool "Device mapper debugging support"
228	depends on BLK_DEV_DM
229	---help---
230	  Enable this for messages that may help debug device-mapper problems.
231
232	  If unsure, say N.
233
234config DM_BUFIO
235       tristate
236       depends on BLK_DEV_DM
237       ---help---
238	 This interface allows you to do buffered I/O on a device and acts
239	 as a cache, holding recently-read blocks in memory and performing
240	 delayed writes.
241
242config DM_BIO_PRISON
243       tristate
244       depends on BLK_DEV_DM
245       ---help---
246	 Some bio locking schemes used by other device-mapper targets
247	 including thin provisioning.
248
249source "drivers/md/persistent-data/Kconfig"
250
251config DM_CRYPT
252	tristate "Crypt target support"
253	depends on BLK_DEV_DM
254	select CRYPTO
255	select CRYPTO_CBC
256	---help---
257	  This device-mapper target allows you to create a device that
258	  transparently encrypts the data on it. You'll need to activate
259	  the ciphers you're going to use in the cryptoapi configuration.
260
261	  For further information on dm-crypt and userspace tools see:
262	  <https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt>
263
264	  To compile this code as a module, choose M here: the module will
265	  be called dm-crypt.
266
267	  If unsure, say N.
268
269config DM_SNAPSHOT
270       tristate "Snapshot target"
271       depends on BLK_DEV_DM
272       select DM_BUFIO
273       ---help---
274         Allow volume managers to take writable snapshots of a device.
275
276config DM_THIN_PROVISIONING
277       tristate "Thin provisioning target"
278       depends on BLK_DEV_DM
279       select DM_PERSISTENT_DATA
280       select DM_BIO_PRISON
281       ---help---
282         Provides thin provisioning and snapshots that share a data store.
283
284config DM_CACHE
285       tristate "Cache target (EXPERIMENTAL)"
286       depends on BLK_DEV_DM
287       default n
288       select DM_PERSISTENT_DATA
289       select DM_BIO_PRISON
290       ---help---
291         dm-cache attempts to improve performance of a block device by
292         moving frequently used data to a smaller, higher performance
293         device.  Different 'policy' plugins can be used to change the
294         algorithms used to select which blocks are promoted, demoted,
295         cleaned etc.  It supports writeback and writethrough modes.
296
297config DM_CACHE_MQ
298       tristate "MQ Cache Policy (EXPERIMENTAL)"
299       depends on DM_CACHE
300       default y
301       ---help---
302         A cache policy that uses a multiqueue ordered by recent hit
303         count to select which blocks should be promoted and demoted.
304         This is meant to be a general purpose policy.  It prioritises
305         reads over writes.
306
307config DM_CACHE_SMQ
308       tristate "Stochastic MQ Cache Policy (EXPERIMENTAL)"
309       depends on DM_CACHE
310       default y
311       ---help---
312         A cache policy that uses a multiqueue ordered by recent hits
313         to select which blocks should be promoted and demoted.
314         This is meant to be a general purpose policy.  It prioritises
315         reads over writes.  This SMQ policy (vs MQ) offers the promise
316         of less memory utilization, improved performance and increased
317         adaptability in the face of changing workloads.
318
319config DM_CACHE_CLEANER
320       tristate "Cleaner Cache Policy (EXPERIMENTAL)"
321       depends on DM_CACHE
322       default y
323       ---help---
324         A simple cache policy that writes back all data to the
325         origin.  Used when decommissioning a dm-cache.
326
327config DM_ERA
328       tristate "Era target (EXPERIMENTAL)"
329       depends on BLK_DEV_DM
330       default n
331       select DM_PERSISTENT_DATA
332       select DM_BIO_PRISON
333       ---help---
334         dm-era tracks which parts of a block device are written to
335         over time.  Useful for maintaining cache coherency when using
336         vendor snapshots.
337
338config DM_MIRROR
339       tristate "Mirror target"
340       depends on BLK_DEV_DM
341       ---help---
342         Allow volume managers to mirror logical volumes, also
343         needed for live data migration tools such as 'pvmove'.
344
345config DM_LOG_USERSPACE
346	tristate "Mirror userspace logging"
347	depends on DM_MIRROR && NET
348	select CONNECTOR
349	---help---
350	  The userspace logging module provides a mechanism for
351	  relaying the dm-dirty-log API to userspace.  Log designs
352	  which are more suited to userspace implementation (e.g.
353	  shared storage logs) or experimental logs can be implemented
354	  by leveraging this framework.
355
356config DM_RAID
357       tristate "RAID 1/4/5/6/10 target"
358       depends on BLK_DEV_DM
359       select MD_RAID1
360       select MD_RAID10
361       select MD_RAID456
362       select BLK_DEV_MD
363       ---help---
364	 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
365
366	 A RAID-5 set of N drives with a capacity of C MB per drive provides
367	 the capacity of C * (N - 1) MB, and protects against a failure
368	 of a single drive. For a given sector (row) number, (N - 1) drives
369	 contain data sectors, and one drive contains the parity protection.
370	 For a RAID-4 set, the parity blocks are present on a single drive,
371	 while a RAID-5 set distributes the parity across the drives in one
372	 of the available parity distribution methods.
373
374	 A RAID-6 set of N drives with a capacity of C MB per drive
375	 provides the capacity of C * (N - 2) MB, and protects
376	 against a failure of any two drives. For a given sector
377	 (row) number, (N - 2) drives contain data sectors, and two
378	 drives contains two independent redundancy syndromes.  Like
379	 RAID-5, RAID-6 distributes the syndromes across the drives
380	 in one of the available parity distribution methods.
381
382config DM_ZERO
383	tristate "Zero target"
384	depends on BLK_DEV_DM
385	---help---
386	  A target that discards writes, and returns all zeroes for
387	  reads.  Useful in some recovery situations.
388
389config DM_MULTIPATH
390	tristate "Multipath target"
391	depends on BLK_DEV_DM
392	# nasty syntax but means make DM_MULTIPATH independent
393	# of SCSI_DH if the latter isn't defined but if
394	# it is, DM_MULTIPATH must depend on it.  We get a build
395	# error if SCSI_DH=m and DM_MULTIPATH=y
396	depends on SCSI_DH || !SCSI_DH
397	---help---
398	  Allow volume managers to support multipath hardware.
399
400config DM_MULTIPATH_QL
401	tristate "I/O Path Selector based on the number of in-flight I/Os"
402	depends on DM_MULTIPATH
403	---help---
404	  This path selector is a dynamic load balancer which selects
405	  the path with the least number of in-flight I/Os.
406
407	  If unsure, say N.
408
409config DM_MULTIPATH_ST
410	tristate "I/O Path Selector based on the service time"
411	depends on DM_MULTIPATH
412	---help---
413	  This path selector is a dynamic load balancer which selects
414	  the path expected to complete the incoming I/O in the shortest
415	  time.
416
417	  If unsure, say N.
418
419config DM_DELAY
420	tristate "I/O delaying target"
421	depends on BLK_DEV_DM
422	---help---
423	A target that delays reads and/or writes and can send
424	them to different devices.  Useful for testing.
425
426	If unsure, say N.
427
428config DM_UEVENT
429	bool "DM uevents"
430	depends on BLK_DEV_DM
431	---help---
432	Generate udev events for DM events.
433
434config DM_FLAKEY
435       tristate "Flakey target"
436       depends on BLK_DEV_DM
437       ---help---
438         A target that intermittently fails I/O for debugging purposes.
439
440config DM_VERITY
441	tristate "Verity target support"
442	depends on BLK_DEV_DM
443	select CRYPTO
444	select CRYPTO_HASH
445	select DM_BUFIO
446	---help---
447	  This device-mapper target creates a read-only device that
448	  transparently validates the data on one underlying device against
449	  a pre-generated tree of cryptographic checksums stored on a second
450	  device.
451
452	  You'll need to activate the digests you're going to use in the
453	  cryptoapi configuration.
454
455	  To compile this code as a module, choose M here: the module will
456	  be called dm-verity.
457
458	  If unsure, say N.
459
460config DM_SWITCH
461	tristate "Switch target support (EXPERIMENTAL)"
462	depends on BLK_DEV_DM
463	---help---
464	  This device-mapper target creates a device that supports an arbitrary
465	  mapping of fixed-size regions of I/O across a fixed set of paths.
466	  The path used for any specific region can be switched dynamically
467	  by sending the target a message.
468
469	  To compile this code as a module, choose M here: the module will
470	  be called dm-switch.
471
472	  If unsure, say N.
473
474config DM_LOG_WRITES
475	tristate "Log writes target support"
476	depends on BLK_DEV_DM
477	---help---
478	  This device-mapper target takes two devices, one device to use
479	  normally, one to log all write operations done to the first device.
480	  This is for use by file system developers wishing to verify that
481	  their fs is writing a consitent file system at all times by allowing
482	  them to replay the log in a variety of ways and to check the
483	  contents.
484
485	  To compile this code as a module, choose M here: the module will
486	  be called dm-log-writes.
487
488	  If unsure, say N.
489
490endif # MD
491