xref: /openbmc/linux/drivers/md/Kconfig (revision 5f32c314)
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 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
168config 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
177source "drivers/md/bcache/Kconfig"
178
179config BLK_DEV_DM_BUILTIN
180	boolean
181
182config BLK_DEV_DM
183	tristate "Device mapper support"
184	select BLK_DEV_DM_BUILTIN
185	---help---
186	  Device-mapper is a low level volume manager.  It works by allowing
187	  people to specify mappings for ranges of logical sectors.  Various
188	  mapping types are available, in addition people may write their own
189	  modules containing custom mappings if they wish.
190
191	  Higher level volume managers such as LVM2 use this driver.
192
193	  To compile this as a module, choose M here: the module will be
194	  called dm-mod.
195
196	  If unsure, say N.
197
198config DM_DEBUG
199	boolean "Device mapper debugging support"
200	depends on BLK_DEV_DM
201	---help---
202	  Enable this for messages that may help debug device-mapper problems.
203
204	  If unsure, say N.
205
206config DM_BUFIO
207       tristate
208       depends on BLK_DEV_DM
209       ---help---
210	 This interface allows you to do buffered I/O on a device and acts
211	 as a cache, holding recently-read blocks in memory and performing
212	 delayed writes.
213
214config DM_BIO_PRISON
215       tristate
216       depends on BLK_DEV_DM
217       ---help---
218	 Some bio locking schemes used by other device-mapper targets
219	 including thin provisioning.
220
221source "drivers/md/persistent-data/Kconfig"
222
223config DM_CRYPT
224	tristate "Crypt target support"
225	depends on BLK_DEV_DM
226	select CRYPTO
227	select CRYPTO_CBC
228	---help---
229	  This device-mapper target allows you to create a device that
230	  transparently encrypts the data on it. You'll need to activate
231	  the ciphers you're going to use in the cryptoapi configuration.
232
233	  Information on how to use dm-crypt can be found on
234
235	  <http://www.saout.de/misc/dm-crypt/>
236
237	  To compile this code as a module, choose M here: the module will
238	  be called dm-crypt.
239
240	  If unsure, say N.
241
242config DM_SNAPSHOT
243       tristate "Snapshot target"
244       depends on BLK_DEV_DM
245       select DM_BUFIO
246       ---help---
247         Allow volume managers to take writable snapshots of a device.
248
249config DM_THIN_PROVISIONING
250       tristate "Thin provisioning target"
251       depends on BLK_DEV_DM
252       select DM_PERSISTENT_DATA
253       select DM_BIO_PRISON
254       ---help---
255         Provides thin provisioning and snapshots that share a data store.
256
257config DM_DEBUG_BLOCK_STACK_TRACING
258	boolean "Keep stack trace of persistent data block lock holders"
259	depends on STACKTRACE_SUPPORT && DM_PERSISTENT_DATA
260	select STACKTRACE
261	---help---
262	  Enable this for messages that may help debug problems with the
263	  block manager locking used by thin provisioning and caching.
264
265	  If unsure, say N.
266
267config DM_CACHE
268       tristate "Cache target (EXPERIMENTAL)"
269       depends on BLK_DEV_DM
270       default n
271       select DM_PERSISTENT_DATA
272       select DM_BIO_PRISON
273       ---help---
274         dm-cache attempts to improve performance of a block device by
275         moving frequently used data to a smaller, higher performance
276         device.  Different 'policy' plugins can be used to change the
277         algorithms used to select which blocks are promoted, demoted,
278         cleaned etc.  It supports writeback and writethrough modes.
279
280config DM_CACHE_MQ
281       tristate "MQ Cache Policy (EXPERIMENTAL)"
282       depends on DM_CACHE
283       default y
284       ---help---
285         A cache policy that uses a multiqueue ordered by recent hit
286         count to select which blocks should be promoted and demoted.
287         This is meant to be a general purpose policy.  It prioritises
288         reads over writes.
289
290config DM_CACHE_CLEANER
291       tristate "Cleaner Cache Policy (EXPERIMENTAL)"
292       depends on DM_CACHE
293       default y
294       ---help---
295         A simple cache policy that writes back all data to the
296         origin.  Used when decommissioning a dm-cache.
297
298config DM_MIRROR
299       tristate "Mirror target"
300       depends on BLK_DEV_DM
301       ---help---
302         Allow volume managers to mirror logical volumes, also
303         needed for live data migration tools such as 'pvmove'.
304
305config DM_LOG_USERSPACE
306	tristate "Mirror userspace logging"
307	depends on DM_MIRROR && NET
308	select CONNECTOR
309	---help---
310	  The userspace logging module provides a mechanism for
311	  relaying the dm-dirty-log API to userspace.  Log designs
312	  which are more suited to userspace implementation (e.g.
313	  shared storage logs) or experimental logs can be implemented
314	  by leveraging this framework.
315
316config DM_RAID
317       tristate "RAID 1/4/5/6/10 target"
318       depends on BLK_DEV_DM
319       select MD_RAID1
320       select MD_RAID10
321       select MD_RAID456
322       select BLK_DEV_MD
323       ---help---
324	 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
325
326	 A RAID-5 set of N drives with a capacity of C MB per drive provides
327	 the capacity of C * (N - 1) MB, and protects against a failure
328	 of a single drive. For a given sector (row) number, (N - 1) drives
329	 contain data sectors, and one drive contains the parity protection.
330	 For a RAID-4 set, the parity blocks are present on a single drive,
331	 while a RAID-5 set distributes the parity across the drives in one
332	 of the available parity distribution methods.
333
334	 A RAID-6 set of N drives with a capacity of C MB per drive
335	 provides the capacity of C * (N - 2) MB, and protects
336	 against a failure of any two drives. For a given sector
337	 (row) number, (N - 2) drives contain data sectors, and two
338	 drives contains two independent redundancy syndromes.  Like
339	 RAID-5, RAID-6 distributes the syndromes across the drives
340	 in one of the available parity distribution methods.
341
342config DM_ZERO
343	tristate "Zero target"
344	depends on BLK_DEV_DM
345	---help---
346	  A target that discards writes, and returns all zeroes for
347	  reads.  Useful in some recovery situations.
348
349config DM_MULTIPATH
350	tristate "Multipath target"
351	depends on BLK_DEV_DM
352	# nasty syntax but means make DM_MULTIPATH independent
353	# of SCSI_DH if the latter isn't defined but if
354	# it is, DM_MULTIPATH must depend on it.  We get a build
355	# error if SCSI_DH=m and DM_MULTIPATH=y
356	depends on SCSI_DH || !SCSI_DH
357	---help---
358	  Allow volume managers to support multipath hardware.
359
360config DM_MULTIPATH_QL
361	tristate "I/O Path Selector based on the number of in-flight I/Os"
362	depends on DM_MULTIPATH
363	---help---
364	  This path selector is a dynamic load balancer which selects
365	  the path with the least number of in-flight I/Os.
366
367	  If unsure, say N.
368
369config DM_MULTIPATH_ST
370	tristate "I/O Path Selector based on the service time"
371	depends on DM_MULTIPATH
372	---help---
373	  This path selector is a dynamic load balancer which selects
374	  the path expected to complete the incoming I/O in the shortest
375	  time.
376
377	  If unsure, say N.
378
379config DM_DELAY
380	tristate "I/O delaying target"
381	depends on BLK_DEV_DM
382	---help---
383	A target that delays reads and/or writes and can send
384	them to different devices.  Useful for testing.
385
386	If unsure, say N.
387
388config DM_UEVENT
389	bool "DM uevents"
390	depends on BLK_DEV_DM
391	---help---
392	Generate udev events for DM events.
393
394config DM_FLAKEY
395       tristate "Flakey target"
396       depends on BLK_DEV_DM
397       ---help---
398         A target that intermittently fails I/O for debugging purposes.
399
400config DM_VERITY
401	tristate "Verity target support"
402	depends on BLK_DEV_DM
403	select CRYPTO
404	select CRYPTO_HASH
405	select DM_BUFIO
406	---help---
407	  This device-mapper target creates a read-only device that
408	  transparently validates the data on one underlying device against
409	  a pre-generated tree of cryptographic checksums stored on a second
410	  device.
411
412	  You'll need to activate the digests you're going to use in the
413	  cryptoapi configuration.
414
415	  To compile this code as a module, choose M here: the module will
416	  be called dm-verity.
417
418	  If unsure, say N.
419
420config DM_SWITCH
421	tristate "Switch target support (EXPERIMENTAL)"
422	depends on BLK_DEV_DM
423	---help---
424	  This device-mapper target creates a device that supports an arbitrary
425	  mapping of fixed-size regions of I/O across a fixed set of paths.
426	  The path used for any specific region can be switched dynamically
427	  by sending the target a message.
428
429	  To compile this code as a module, choose M here: the module will
430	  be called dm-switch.
431
432	  If unsure, say N.
433
434endif # MD
435