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52826846 | 1 | .\" -*- nroff -*- |
e5329c37 | 2 | .TH MDADM 8 "" v1.7.0 |
52826846 | 3 | .SH NAME |
9a9dab36 | 4 | mdadm \- manage MD devices |
cd29a5c8 NB |
5 | .I aka |
6 | Linux Software Raid. | |
7 | ||
52826846 NB |
8 | .SH SYNOPSIS |
9 | ||
e0d19036 | 10 | .BI mdadm " [mode] <raiddevice> [options] <component-devices>" |
52826846 NB |
11 | |
12 | .SH DESCRIPTION | |
13 | RAID devices are virtual devices created from two or more | |
cd29a5c8 NB |
14 | real block devices. This allows multiple devices (typically disk |
15 | drives or partitions there-of) to be combined into a single device to | |
16 | hold (for example) a single filesystem. | |
2d465520 | 17 | Some RAID levels include redundancy and so can survive some degree of |
cd29a5c8 NB |
18 | device failure. |
19 | ||
2d465520 NB |
20 | Linux Software RAID devices are implemented through the md (Multiple |
21 | Devices) device driver. | |
cd29a5c8 NB |
22 | |
23 | Currently, Linux supports | |
24 | .B LINEAR | |
25 | md devices, | |
26 | .B RAID0 | |
27 | (striping), | |
28 | .B RAID1 | |
29 | (mirroring), | |
d013a55e NB |
30 | .BR RAID4 , |
31 | .BR RAID5 , | |
98c6faba | 32 | .BR RAID6 , |
cd29a5c8 | 33 | and |
cd29a5c8 | 34 | .BR MULTIPATH . |
d013a55e NB |
35 | |
36 | .B MULTIPATH is not a Software RAID mechanism, but does involve | |
37 | multiple devices. For | |
38 | .B MULTIPATH | |
39 | each device is a path to one common physical storage device. | |
40 | ||
52826846 | 41 | |
9a9dab36 | 42 | .B mdadm |
11a3e71d NB |
43 | is a program that can be used to create, manage, and monitor |
44 | MD devices. As | |
cd29a5c8 NB |
45 | such it provides a similar set of functionality to the |
46 | .B raidtools | |
47 | packages. | |
48 | The key differences between | |
9a9dab36 | 49 | .B mdadm |
cd29a5c8 NB |
50 | and |
51 | .B raidtools | |
52 | are: | |
53 | .IP \(bu 4 | |
9a9dab36 | 54 | .B mdadm |
cd29a5c8 NB |
55 | is a single program and not a collection of programs. |
56 | .IP \(bu 4 | |
9a9dab36 | 57 | .B mdadm |
cd29a5c8 | 58 | can perform (almost) all of its functions without having a |
5787fa49 | 59 | configuration file and does not use one by default. Also |
2d465520 NB |
60 | .B mdadm |
61 | helps with management of the configuration | |
cd29a5c8 NB |
62 | file. |
63 | .IP \(bu 4 | |
9a9dab36 | 64 | .B mdadm |
e0d19036 | 65 | can provide information about your arrays (through Query, Detail, and Examine) |
cd29a5c8 NB |
66 | that |
67 | .B raidtools | |
68 | cannot. | |
5787fa49 NB |
69 | .P |
70 | .I mdadm | |
71 | does not use | |
72 | .IR /etc/raidtab , | |
73 | the | |
74 | .B raidtools | |
75 | configuration file, at all. It has a different configuration file | |
76 | with a different format and an different purpose. | |
52826846 NB |
77 | |
78 | .SH MODES | |
dd0781e5 | 79 | mdadm has 7 major modes of operation: |
cd29a5c8 NB |
80 | .TP |
81 | .B Assemble | |
82 | Assemble the parts of a previously created | |
52826846 NB |
83 | array into an active array. Components can be explicitly given |
84 | or can be searched for. | |
9a9dab36 | 85 | .B mdadm |
cd29a5c8 NB |
86 | checks that the components |
87 | do form a bona fide array, and can, on request, fiddle superblock | |
88 | information so as to assemble a faulty array. | |
89 | ||
90 | .TP | |
91 | .B Build | |
92 | Build a legacy array without per-device superblocks. | |
93 | ||
94 | .TP | |
95 | .B Create | |
96 | Create a new array with per-device superblocks. | |
97 | '''It can progress | |
98 | '''in several step create-add-add-run or it can all happen with one command. | |
99 | ||
100 | .TP | |
e0d19036 NB |
101 | .B Manage |
102 | This is for doing things to specific components of an array such as | |
103 | adding new spares and removing faulty devices. | |
cd29a5c8 NB |
104 | |
105 | .TP | |
e0d19036 NB |
106 | .B Misc |
107 | This mode allows operations on independent devices such as examine MD | |
108 | superblocks, erasing old superblocks and stopping active arrays. | |
cd29a5c8 NB |
109 | |
110 | .TP | |
111 | .B "Follow or Monitor" | |
5787fa49 | 112 | Monitor one or more md devices and act on any state changes. This is |
98c6faba NB |
113 | only meaningful for raid1, 4, 5, 6 or multipath arrays as |
114 | only these have interesting state. raid0 or linear never have | |
115 | missing, spare, or failed drives, so there is nothing to monitor. | |
5787fa49 | 116 | |
dd0781e5 NB |
117 | .TP |
118 | .B "Grow" | |
119 | Grow (or shrink) an array, or otherwise reshape it in some way. | |
120 | Currently supported growth options including changing the active size | |
121 | of componenet devices in RAID level 1/4/5/6 and changing the number of | |
122 | active devices in RAID1. | |
cd29a5c8 | 123 | |
52826846 NB |
124 | .SH OPTIONS |
125 | ||
126 | Available options are: | |
127 | ||
cd29a5c8 NB |
128 | .TP |
129 | .BR -A ", " --assemble | |
2d465520 | 130 | Assemble a pre-existing array. |
52826846 | 131 | |
cd29a5c8 NB |
132 | .TP |
133 | .BR -B ", " --build | |
134 | Build a legacy array without superblocks. | |
52826846 | 135 | |
cd29a5c8 NB |
136 | .TP |
137 | .BR -C ", " --create | |
138 | Create a new array. | |
52826846 | 139 | |
e0d19036 NB |
140 | .TP |
141 | .BR -Q ", " --query | |
142 | Examine a device to see | |
143 | (1) if it is an md device and (2) if it is a component of an md | |
144 | array. | |
145 | Information about what is discovered is presented. | |
146 | ||
cd29a5c8 NB |
147 | .TP |
148 | .BR -D ", " --detail | |
149 | Print detail of one or more md devices. | |
52826846 | 150 | |
cd29a5c8 NB |
151 | .TP |
152 | .BR -E ", " --examine | |
153 | Print content of md superblock on device(s). | |
52826846 | 154 | |
cd29a5c8 NB |
155 | .TP |
156 | .BR -F ", " --follow ", " --monitor | |
157 | Select | |
158 | .B Monitor | |
159 | mode. | |
52826846 | 160 | |
dd0781e5 NB |
161 | .TP |
162 | .BR -G ", " --grow | |
163 | Change the size or shape of an active array. | |
164 | ||
cd29a5c8 NB |
165 | .TP |
166 | .BR -h ", " --help | |
56eedc1a NB |
167 | Display help message or, after above option, mode specific help |
168 | message. | |
169 | ||
170 | .TP | |
171 | .B --help-options | |
172 | Display more detailed help about command line parsing and some commonly | |
173 | used options. | |
52826846 | 174 | |
cd29a5c8 NB |
175 | .TP |
176 | .BR -V ", " --version | |
9a9dab36 | 177 | Print version information for mdadm. |
52826846 | 178 | |
cd29a5c8 NB |
179 | .TP |
180 | .BR -v ", " --verbose | |
181 | Be more verbose about what is happening. | |
52826846 | 182 | |
cd29a5c8 NB |
183 | .TP |
184 | .BR -b ", " --brief | |
185 | Be less verbose. This is used with | |
186 | .B --detail | |
187 | and | |
188 | .BR --examine . | |
52826846 | 189 | |
e0d19036 NB |
190 | .TP |
191 | .BR -f ", " --force | |
192 | Be more forceful about certain operations. See the various modes of | |
193 | the exact meaning of this option in different contexts. | |
194 | ||
195 | .TP | |
196 | .BR -c ", " --config= | |
197 | Specify the config file. Default is | |
198 | .BR /etc/mdadm.conf . | |
5787fa49 NB |
199 | If the config file given is |
200 | .B partitions | |
201 | then nothing will be read, but | |
202 | .I mdadm | |
203 | will act as though the config file contained exactly | |
204 | .B "DEVICE partitions" | |
205 | and will read | |
206 | .B /proc/partitions | |
207 | to find a list of devices to scan. | |
d013a55e NB |
208 | If the word |
209 | .B none | |
210 | is given for the config file, then | |
211 | .I mdadm | |
212 | will act as though the config file were empty. | |
e0d19036 NB |
213 | |
214 | .TP | |
215 | .BR -s ", " --scan | |
216 | scan config file or | |
217 | .B /proc/mdstat | |
218 | for missing information. | |
219 | In general, this option gives | |
220 | .B mdadm | |
221 | permission to get any missing information, like component devices, | |
222 | array devices, array identities, and alert destination from the | |
223 | configuration file: | |
224 | .BR /etc/mdadm.conf . | |
225 | One exception is MISC mode when using | |
226 | .B --detail | |
227 | or | |
228 | .B --stop | |
229 | in which case | |
230 | .B --scan | |
231 | says to get a list of array devices from | |
232 | .BR /proc/mdstat . | |
233 | ||
cd29a5c8 | 234 | .SH For create or build: |
52826846 | 235 | |
cd29a5c8 NB |
236 | .TP |
237 | .BR -c ", " --chunk= | |
238 | Specify chunk size of kibibytes. The default is 64. | |
52826846 | 239 | |
cd29a5c8 NB |
240 | .TP |
241 | .BR --rounding= | |
242 | Specify rounding factor for linear array (==chunk size) | |
52826846 | 243 | |
cd29a5c8 NB |
244 | .TP |
245 | .BR -l ", " --level= | |
aa88f531 NB |
246 | Set raid level. When used with |
247 | .IR --create , | |
98c6faba NB |
248 | options are: linear, raid0, 0, stripe, raid1, 1, mirror, raid4, 4, |
249 | raid5, 5, raid6, 6, multipath, mp. Obviously some of these are synonymous. | |
aa88f531 NB |
250 | |
251 | When used with | |
252 | .IR --build , | |
253 | only linear, raid0, 0, stripe are valid. | |
52826846 | 254 | |
cd29a5c8 NB |
255 | .TP |
256 | .BR -p ", " --parity= | |
257 | Set raid5 parity algorithm. Options are: | |
2d465520 NB |
258 | left-asymmetric, |
259 | left-symmetric, | |
260 | right-asymmetric, | |
261 | right-symmetric, | |
262 | la, ra, ls, rs. The default is left-symmetric. | |
52826846 | 263 | |
cd29a5c8 NB |
264 | .TP |
265 | .BR --layout= | |
266 | same as --parity | |
52826846 | 267 | |
cd29a5c8 | 268 | .TP |
b83d95f3 | 269 | .BR -n ", " --raid-devices= |
5787fa49 NB |
270 | Specify the number of active devices in the array. This, plus the |
271 | number of spare devices (see below) must equal the number of | |
272 | .I component-devices | |
d013a55e | 273 | (including "\fBmissing\fP" devices) |
dd0781e5 NB |
274 | that are listed on the command line for |
275 | .BR --create . | |
276 | Setting a value of 1 is probably | |
aa88f531 NB |
277 | a mistake and so requires that |
278 | .B --force | |
279 | be specified first. A value of 1 will then be allowed for linear, | |
280 | multipath, raid0 and raid1. It is never allowed for raid4 or raid5. | |
281 | .br | |
dd0781e5 NB |
282 | This number can only be changed using |
283 | .B --grow | |
284 | for RAID1 arrays, and only on kernels which provide necessary support. | |
cd29a5c8 NB |
285 | |
286 | .TP | |
b83d95f3 | 287 | .BR -x ", " --spare-devices= |
5787fa49 NB |
288 | Specify the number of spare (eXtra) devices in the initial array. |
289 | Spares can also be added | |
290 | and removed later. The number of component devices listed | |
291 | on the command line must equal the number of raid devices plus the | |
292 | number of spare devices. | |
293 | ||
cd29a5c8 NB |
294 | |
295 | .TP | |
296 | .BR -z ", " --size= | |
98c6faba | 297 | Amount (in Kibibytes) of space to use from each drive in RAID1/4/5/6. |
cd29a5c8 NB |
298 | This must be a multiple of the chunk size, and must leave about 128Kb |
299 | of space at the end of the drive for the RAID superblock. | |
300 | If this is not specified | |
301 | (as it normally is not) the smallest drive (or partition) sets the | |
302 | size, though if there is a variance among the drives of greater than 1%, a warning is | |
303 | issued. | |
52826846 | 304 | |
dd0781e5 NB |
305 | This value can be set with |
306 | .B --grow | |
307 | for RAID level 1/4/5/6. If the array was created with a size smaller | |
308 | than the currently active drives, the extra space can be accessed | |
309 | using | |
310 | .BR --grow . | |
311 | ||
312 | .TP | |
313 | .BR --assume-clean | |
314 | Tell | |
315 | .I mdadm | |
316 | that the array pre-existed and is known to be clean. This is only | |
317 | really useful for Building RAID1 array. Only use this if you really | |
318 | know what you are doing. This is currently only supported for --build. | |
319 | ||
320 | .TP | |
321 | .BR -R ", " --run | |
322 | Insist that | |
323 | .I mdadm | |
324 | run the array, even if some of the components | |
325 | appear to be active in another array or filesystem. Normally | |
326 | .I mdadm | |
327 | will ask for confirmation before including such components in an | |
328 | array. This option causes that question to be suppressed. | |
329 | ||
330 | .TP | |
331 | .BR -f ", " --force | |
332 | Insist that | |
333 | .I mdadm | |
334 | accept the geometry and layout specified without question. Normally | |
335 | .I mdadm | |
336 | will not allow creation of an array with only one device, and will try | |
337 | to create a raid5 array with one missing drive (as this makes the | |
338 | initial resync work faster). With | |
339 | .BR --force , | |
340 | .I mdadm | |
341 | will not try to be so clever. | |
342 | ||
343 | .TP | |
344 | .BR -a ", " "--auto{=no,yes,md,mdp,part,p}{NN}" | |
345 | Instruct mdadm to create the device file if needed, and to allocate | |
346 | an unused minor number. "yes" or "md" causes a non-partitionable array | |
347 | to be used. "mdp", "part" or "p" causes a partitionable array (2.6 and | |
348 | later) to be used. The argumentment can also come immediately after | |
349 | "-a". e.g. "-ap". | |
350 | ||
351 | For partitionable arrays, | |
352 | .I mdadm | |
353 | will create the device file for the whole array and for the first 4 | |
354 | partitions. A different number of partitions can be specified at the | |
355 | end of this option (e.g. | |
356 | .BR --auto=p7 ). | |
357 | If the device name ends with a digit, the partition names add an | |
358 | underscore, a 'p', and a number, e.g. "/dev/home1_p3". If there is no | |
359 | trailing digit, then the partition names just have a number added, | |
360 | e.g. "/dev/scratch3". | |
361 | ||
52826846 NB |
362 | .SH For assemble: |
363 | ||
cd29a5c8 NB |
364 | .TP |
365 | .BR -u ", " --uuid= | |
366 | uuid of array to assemble. Devices which don't have this uuid are | |
367 | excluded | |
368 | ||
369 | .TP | |
370 | .BR -m ", " --super-minor= | |
371 | Minor number of device that array was created for. Devices which | |
372 | don't have this minor number are excluded. If you create an array as | |
2d465520 | 373 | /dev/md1, then all superblocks will contain the minor number 1, even if |
cd29a5c8 NB |
374 | the array is later assembled as /dev/md2. |
375 | ||
d013a55e NB |
376 | Giving the literal word "dev" for |
377 | .B --super-minor | |
378 | will cause | |
379 | .I mdadm | |
380 | to use the minor number of the md device that is being assembled. | |
381 | e.g. when assembling | |
382 | .BR /dev/md0 , | |
383 | .M --super-minor=dev | |
384 | will look for super blocks with a minor number of 0. | |
385 | ||
cd29a5c8 NB |
386 | .TP |
387 | .BR -f ", " --force | |
52826846 NB |
388 | Assemble the array even if some superblocks appear out-of-date |
389 | ||
cd29a5c8 NB |
390 | .TP |
391 | .BR -R ", " --run | |
392 | Attempt to start the array even if fewer drives were given than are | |
393 | needed for a full array. Normally if not all drives are found and | |
394 | .B --scan | |
395 | is not used, then the array will be assembled but not started. | |
396 | With | |
397 | .B --run | |
398 | an attempt will be made to start it anyway. | |
52826846 | 399 | |
dd0781e5 NB |
400 | .TP |
401 | .BR -a ", " "--auto{=no,yes,md,mdp,part}" | |
402 | See this option under Create and Build options. | |
403 | ||
5787fa49 NB |
404 | .TP |
405 | .BR -U ", " --update= | |
406 | Update the superblock on each device while assembling the array. The | |
feb716e9 NB |
407 | argument given to this flag can be one of |
408 | .BR sparc2.2 , | |
409 | .BR summaries , | |
e5329c37 | 410 | .BR resync , |
5787fa49 NB |
411 | or |
412 | .BR super-minor . | |
413 | ||
414 | The | |
415 | .B sparc2.2 | |
416 | option will adjust the superblock of an array what was created on a Sparc | |
417 | machine running a patched 2.2 Linux kernel. This kernel got the | |
418 | alignment of part of the superblock wrong. You can use the | |
419 | .B "--examine --sparc2.2" | |
420 | option to | |
421 | .I mdadm | |
422 | to see what effect this would have. | |
423 | ||
424 | The | |
425 | .B super-minor | |
426 | option will update the | |
427 | .B "prefered minor" | |
428 | field on each superblock to match the minor number of the array being | |
feb716e9 | 429 | assembled. This is not needed on 2.6 and later kernels as they make |
5787fa49 NB |
430 | this adjustment automatically. |
431 | ||
e5329c37 NB |
432 | The |
433 | .B resync | |
434 | option will cause the array to be marked | |
435 | .I dirty | |
436 | meaning that any redundancy in the array (e.g. parity for raid5, | |
437 | copies for raid1) may be incorrect. This will cause the raid system | |
438 | to perform a "resync" pass to make sure that all redundant information | |
439 | is correct. | |
440 | ||
feb716e9 NB |
441 | The |
442 | .B summaries | |
443 | option will correct the summaries in the superblock. That is the | |
444 | counts of total, working, active, failed, and spare devices. | |
5787fa49 | 445 | |
e0d19036 | 446 | .SH For Manage mode: |
52826846 | 447 | |
cd29a5c8 NB |
448 | .TP |
449 | .BR -a ", " --add | |
450 | '''add, or | |
451 | hotadd listed devices. | |
52826846 | 452 | |
cd29a5c8 NB |
453 | .TP |
454 | .BR -r ", " --remove | |
2d465520 | 455 | remove listed devices. They must not be active. i.e. they should |
cd29a5c8 | 456 | be failed or spare devices. |
52826846 | 457 | |
cd29a5c8 NB |
458 | .TP |
459 | .BR -f ", " --fail | |
460 | mark listed devices as faulty. | |
52826846 | 461 | |
cd29a5c8 NB |
462 | .TP |
463 | .BR --set-faulty | |
464 | same as --fail. | |
52826846 | 465 | |
5787fa49 NB |
466 | .SH For Examine mode: |
467 | ||
468 | .TP | |
469 | .B --sparc2.2 | |
470 | In an array was created on a 2.2 Linux kernel patched with RAID | |
471 | support, the superblock will have been created incorrectly, or at | |
472 | least incompatibly with 2.4 and later kernels. Using the | |
473 | .B --sparc2.2 | |
474 | flag with | |
475 | .B --examine | |
476 | will fix the superblock before displaying it. If this appears to do | |
477 | the right thing, then the array can be successfully assembled using | |
478 | .BR "--assemble --update=sparc2.2" . | |
479 | ||
e0d19036 NB |
480 | .SH For Misc mode: |
481 | ||
cd29a5c8 NB |
482 | .TP |
483 | .BR -R ", " --run | |
484 | start a partially built array. | |
52826846 | 485 | |
cd29a5c8 NB |
486 | .TP |
487 | .BR -S ", " --stop | |
488 | deactivate array, releasing all resources. | |
52826846 | 489 | |
cd29a5c8 NB |
490 | .TP |
491 | .BR -o ", " --readonly | |
492 | mark array as readonly. | |
52826846 | 493 | |
cd29a5c8 NB |
494 | .TP |
495 | .BR -w ", " --readwrite | |
496 | mark array as readwrite. | |
52826846 | 497 | |
e0d19036 NB |
498 | .TP |
499 | .B --zero-superblock | |
500 | If the device contains a valid md superblock, the block is | |
501 | over-written with zeros. With | |
502 | --force | |
503 | the block where the superblock would be is over-written even if it | |
504 | doesn't appear to be valid. | |
52826846 | 505 | |
feb716e9 NB |
506 | .TP |
507 | .BR -t ", " --test | |
508 | When used with | |
509 | .BR --detail , | |
510 | the exit status of | |
511 | .I mdadm | |
512 | is set to reflect the status of the device. | |
513 | ||
e0d19036 NB |
514 | .SH For Monitor mode: |
515 | .TP | |
516 | .BR -m ", " --mail | |
517 | Give a mail address to send alerts to. | |
518 | ||
519 | .TP | |
520 | .BR -p ", " --program ", " --alert | |
521 | Give a program to be run whenever an event is detected. | |
522 | ||
523 | .TP | |
524 | .BR -d ", " --delay | |
525 | Give a delay in seconds. | |
526 | .B mdadm | |
527 | polls the md arrays and then waits this many seconds before polling | |
528 | again. The default is 60 seconds. | |
529 | ||
d013a55e NB |
530 | .TP |
531 | .BR -f ", " --daemonise | |
532 | Tell | |
533 | .B mdadm | |
534 | to run as a background daemon if it decides to monitor anything. This | |
535 | causes it to fork and run in the child, and to disconnect form the | |
536 | terminal. The process id of the child is written to stdout. | |
537 | This is useful with | |
538 | .B --scan | |
539 | which will only continue monitoring if a mail address or alert program | |
540 | is found in the config file. | |
541 | ||
aa88f531 NB |
542 | .TP |
543 | .BR -1 ", " --oneshot | |
544 | Check arrays only once. This will generate | |
545 | .B NewArray | |
546 | events and more significantly | |
547 | .B DegradedArray | |
548 | events. Running | |
549 | .in +5 | |
550 | .B " mdadm --monitor --scan -1" | |
551 | .in -5 | |
552 | from a cron script will ensure regular notification of any degraded arrays. | |
553 | ||
98c6faba NB |
554 | .TP |
555 | .BR -t ", " --test | |
556 | Generate a | |
557 | .B TestMessage | |
558 | alert for every array found at startup. This alert gets mailed and | |
559 | passed to the alert program. This can be used for testing that alert | |
560 | message to get through successfully. | |
561 | ||
e0d19036 | 562 | .SH ASSEMBLE MODE |
52826846 | 563 | |
cd29a5c8 NB |
564 | .HP 12 |
565 | Usage: | |
9a9dab36 | 566 | .B mdadm --assemble |
5787fa49 NB |
567 | .I md-device options-and-component-devices... |
568 | .HP 12 | |
569 | Usage: | |
570 | .B mdadm --assemble --scan | |
571 | .I md-devices-and-options... | |
cd29a5c8 NB |
572 | .HP 12 |
573 | Usage: | |
9a9dab36 | 574 | .B mdadm --assemble --scan |
cd29a5c8 | 575 | .I options... |
52826846 | 576 | |
cd29a5c8 | 577 | .PP |
52826846 | 578 | This usage assembles one or more raid arrays from pre-existing components. |
9a9dab36 | 579 | For each array, mdadm needs to know the md device, the identity of the |
e0d19036 | 580 | array, and a number of component-devices. These can be found in a number of ways. |
52826846 | 581 | |
5787fa49 NB |
582 | In the first usage example (without the |
583 | .BR --scan ) | |
584 | the first device given is the md device. | |
585 | In the second usage example, all devices listed are treated as md | |
586 | devices and assembly is attempted. | |
587 | In the third (where no devices are listed) all md devices that are | |
588 | listed in the configuration file are assembled. | |
52826846 | 589 | |
d013a55e NB |
590 | If precisely one device is listed, but |
591 | .B --scan | |
dd0781e5 | 592 | is not given, then |
d013a55e NB |
593 | .I mdadm |
594 | acts as though | |
595 | .B --scan | |
596 | was given and identify information is extracted from the configuration file. | |
597 | ||
cd29a5c8 | 598 | The identity can be given with the |
52826846 | 599 | .B --uuid |
cd29a5c8 NB |
600 | option, with the |
601 | .B --super-minor | |
5787fa49 | 602 | option, can be found in the config file, or will be taken from the |
e0d19036 | 603 | super block on the first component-device listed on the command line. |
52826846 NB |
604 | |
605 | Devices can be given on the | |
606 | .B --assemble | |
5787fa49 NB |
607 | command line or in the config file. Only devices which have an md |
608 | superblock which contains the right identity will be considered for | |
609 | any array. | |
52826846 NB |
610 | |
611 | The config file is only used if explicitly named with | |
612 | .B --config | |
d013a55e | 613 | or requested with (a possibly implicit) |
52826846 NB |
614 | .B --scan. |
615 | In the later case, | |
9a9dab36 | 616 | .B /etc/mdadm.conf |
52826846 NB |
617 | is used. |
618 | ||
619 | If | |
620 | .B --scan | |
cd29a5c8 NB |
621 | is not given, then the config file will only be used to find the |
622 | identity of md arrays. | |
52826846 | 623 | |
2d465520 | 624 | Normally the array will be started after it is assembled. However if |
cd29a5c8 | 625 | .B --scan |
2d465520 | 626 | is not given and insufficient drives were listed to start a complete |
cd29a5c8 NB |
627 | (non-degraded) array, then the array is not started (to guard against |
628 | usage errors). To insist that the array be started in this case (as | |
98c6faba | 629 | may work for RAID1, 4, 5 or 6), give the |
cd29a5c8 NB |
630 | .B --run |
631 | flag. | |
52826846 | 632 | |
dd0781e5 NB |
633 | If an |
634 | .B auto | |
635 | option is given, either on the command line (--auto) or in the | |
636 | configuration file (e.g. auto=part), then | |
637 | .I mdadm | |
638 | will create the md device if necessary or will re-create it if it | |
639 | doesn't look usable as it is. | |
640 | ||
641 | This can be useful for handling partitioned devices (which don't have | |
642 | a stable device number - it can change after a reboot) and when using | |
643 | "udev" to manage your | |
644 | .B /dev | |
645 | tree (udev cannot handle md devices because of the unusual device | |
646 | initialisation conventions). | |
647 | ||
648 | If the option to "auto" is "mdp" or "part" or (on the command line | |
649 | only) "p", then mdadm will create a partitionable array, using the | |
650 | first free one that is not inuse, and does not already have an entry | |
651 | in /dev (apart from numeric /dev/md* entries). | |
652 | ||
653 | If the option to "auto" is "yes" or "md" or (on the command line) | |
654 | nothing, then mdadm will create a traditional, non-partitionable md | |
655 | array. | |
656 | ||
657 | It is expected that the "auto" functionality will be used to create | |
658 | device entries with meaningful names such as "/dev/md/home" or | |
659 | "/dev/md/root", rather than names based on the numerical array number. | |
660 | ||
661 | When using this option to create a partitionable array, the device | |
662 | files for the first 4 partitions are also created. If a different | |
663 | number is required it can be simply appended to the auto option. | |
664 | e.g. "auto=part8". Partition names are created by appending a digit | |
665 | string to the device name, with an intervening "_p" if the device name | |
666 | ends with a digit. | |
667 | ||
668 | The | |
669 | .B --auto | |
670 | option is also available in Build and Create modes. As those modes do | |
671 | not use a config file, the "auto=" config option does not apply to | |
672 | these modes. | |
52826846 | 673 | |
cd29a5c8 | 674 | .SH BUILD MODE |
52826846 | 675 | |
cd29a5c8 NB |
676 | .HP 12 |
677 | Usage: | |
9a9dab36 | 678 | .B mdadm --build |
cd29a5c8 NB |
679 | .I device |
680 | .BI --chunk= X | |
681 | .BI --level= Y | |
b83d95f3 | 682 | .BI --raid-devices= Z |
cd29a5c8 NB |
683 | .I devices |
684 | ||
685 | .PP | |
52826846 | 686 | This usage is similar to |
cd29a5c8 | 687 | .BR --create . |
52826846 | 688 | The difference is that it creates a legacy array without a superblock. With |
cd29a5c8 | 689 | these arrays there is no difference between initially creating the array and |
52826846 NB |
690 | subsequently assembling the array, except that hopefully there is useful |
691 | data there in the second case. | |
692 | ||
cd29a5c8 NB |
693 | The level may only be 0, raid0, or linear. All devices must be listed |
694 | and the array will be started once complete. | |
695 | ||
696 | .SH CREATE MODE | |
697 | ||
698 | .HP 12 | |
699 | Usage: | |
9a9dab36 | 700 | .B mdadm --create |
cd29a5c8 NB |
701 | .I device |
702 | .BI --chunk= X | |
703 | .BI --level= Y | |
704 | .br | |
b83d95f3 | 705 | .BI --raid-devices= Z |
cd29a5c8 NB |
706 | .I devices |
707 | ||
708 | .PP | |
709 | This usage will initialise a new md array, associate some devices with | |
710 | it, and activate the array. | |
711 | ||
dd0781e5 NB |
712 | This the |
713 | .B --auto | |
714 | option is given (as described in more detail in the section on | |
715 | Assemble mode), then the md device will be created with a suitable | |
716 | device number if necessary. | |
717 | ||
cd29a5c8 | 718 | As devices are added, they are checked to see if they contain raid |
2d465520 | 719 | superblocks or filesystems. They are also checked to see if the variance in |
cd29a5c8 NB |
720 | device size exceeds 1%. |
721 | ||
722 | If any discrepancy is found, the array will not automatically be run, though | |
723 | the presence of a | |
724 | .B --run | |
725 | can override this caution. | |
726 | ||
2d465520 | 727 | To create a "degraded" array in which some devices are missing, simply |
d013a55e | 728 | give the word "\fBmissing\fP" |
2d465520 NB |
729 | in place of a device name. This will cause |
730 | .B mdadm | |
731 | to leave the corresponding slot in the array empty. | |
732 | For a RAID4 or RAID5 array at most one slot can be | |
98c6faba | 733 | "\fBmissing\fP"; for a RAID6 array at most two slots. |
2d465520 NB |
734 | For a RAID1 array, only one real device needs to be given. All of the |
735 | others can be | |
d013a55e | 736 | "\fBmissing\fP". |
2d465520 | 737 | |
feb716e9 NB |
738 | When creating a RAID5 array, |
739 | .B mdadm | |
740 | will automatically create a degraded array with an extra spare drive. | |
741 | This is because building the spare into a degraded array is in general faster than resyncing | |
742 | the parity on a non-degraded, but not clean, array. This feature can | |
743 | be over-ridden with the | |
744 | -I --force | |
745 | option. | |
746 | ||
cd29a5c8 NB |
747 | '''If the |
748 | '''.B --size | |
e0d19036 | 749 | '''option is given, it is not necessary to list any component-devices in this command. |
cd29a5c8 NB |
750 | '''They can be added later, before a |
751 | '''.B --run. | |
752 | '''If no | |
753 | '''.B --size | |
754 | '''is given, the apparent size of the smallest drive given is used. | |
755 | ||
756 | The General Management options that are valid with --create are: | |
757 | .TP | |
758 | .B --run | |
dd0781e5 | 759 | insist on running the array even if some devices look like they might |
cd29a5c8 NB |
760 | be in use. |
761 | ||
762 | .TP | |
763 | .B --readonly | |
764 | start the array readonly - not supported yet. | |
52826846 | 765 | |
e0d19036 | 766 | .SH MANAGE MODE |
cd29a5c8 NB |
767 | .HP 12 |
768 | Usage: | |
e0d19036 NB |
769 | .B mdadm |
770 | .I device | |
771 | .I options... devices... | |
cd29a5c8 NB |
772 | .PP |
773 | ||
e0d19036 NB |
774 | This usage will allow individual devices in an array to be failed, |
775 | removed or added. It is possible to perform multiple operations with | |
776 | on command. For example: | |
777 | .br | |
5787fa49 | 778 | .B " mdadm /dev/md0 -f /dev/hda1 -r /dev/hda1 -a /dev/hda1" |
e0d19036 NB |
779 | .br |
780 | will firstly mark | |
781 | .B /dev/hda1 | |
782 | as faulty in | |
783 | .B /dev/md0 | |
784 | and will then remove it from the array and finally add it back | |
2d465520 | 785 | in as a spare. However only one md array can be affected by a single |
e0d19036 NB |
786 | command. |
787 | ||
788 | .SH MISC MODE | |
789 | .HP 12 | |
790 | Usage: | |
9a9dab36 | 791 | .B mdadm |
e0d19036 NB |
792 | .I options ... |
793 | .I devices ... | |
794 | .PP | |
cd29a5c8 | 795 | |
e0d19036 NB |
796 | MISC mode includes a number if distinct operations that |
797 | operate on distinct devices. The operations are: | |
798 | .TP | |
799 | --query | |
800 | The device is examined to see if it is | |
801 | (1) an active md array, or | |
802 | (2) a component of an md array. | |
803 | The information discovered is reported. | |
804 | ||
805 | .TP | |
806 | --detail | |
2d465520 NB |
807 | The device should be an active md device. |
808 | .B mdadm | |
809 | will display a detailed description of the array. | |
cd29a5c8 | 810 | .B --brief |
2d465520 NB |
811 | or |
812 | .B --scan | |
813 | will cause the output to be less detailed and the format to be | |
e0d19036 | 814 | suitable for inclusion in |
9a9dab36 | 815 | .BR /etc/mdadm.conf . |
feb716e9 NB |
816 | The exit status of |
817 | .I mdadm | |
818 | will normally be 0 unless | |
819 | .I mdadm | |
820 | failed to get useful information about the device(s). However if the | |
821 | .B --test | |
822 | option is given, then the exit status will be: | |
823 | .RS | |
824 | .TP | |
825 | 0 | |
826 | The array is functioning normally. | |
827 | .TP | |
828 | 1 | |
829 | The array has at least one failed device. | |
830 | .TP | |
831 | 2 | |
832 | The array has multiple failed devices and hence is unusable (raid4 or | |
833 | raid5). | |
834 | .TP | |
835 | 4 | |
836 | There was an error while trying to get information about the device. | |
837 | .RE | |
cd29a5c8 | 838 | |
e0d19036 NB |
839 | .TP |
840 | --examine | |
2d465520 NB |
841 | The device should be a component of an md array. |
842 | .B mdadm | |
843 | will read the md superblock of the device and display the contents. | |
e0d19036 NB |
844 | If |
845 | .B --brief | |
846 | is given, or | |
847 | .B --scan | |
848 | then multiple devices that are components of the one array | |
849 | are grouped together and reported in a single entry suitable | |
850 | for inclusion in | |
851 | .BR /etc/mdadm.conf . | |
852 | ||
2d465520 | 853 | Having |
e0d19036 NB |
854 | .B --scan |
855 | without listing any devices will cause all devices listed in the | |
856 | config file to be examined. | |
857 | ||
858 | .TP | |
859 | --stop | |
98c6faba NB |
860 | The devices should be active md arrays which will be deactivated, as |
861 | long as they are not currently in use. | |
e0d19036 NB |
862 | |
863 | .TP | |
864 | --run | |
865 | This will fully activate a partially assembled md array. | |
866 | ||
867 | .TP | |
868 | --readonly | |
869 | This will mark an active array as read-only, providing that it is | |
870 | not currently being used. | |
871 | ||
872 | .TP | |
873 | --readwrite | |
874 | This will change a | |
875 | .B readonly | |
876 | array back to being read/write. | |
877 | ||
2d465520 NB |
878 | .TP |
879 | --scan | |
880 | For all operations except | |
881 | .BR --examine , | |
882 | .B --scan | |
883 | will cause the operation to be applied to all arrays listed in | |
884 | .BR /proc/mdstat . | |
885 | For | |
886 | .BR --examine, | |
887 | .B --scan | |
888 | causes all devices listed in the config file to be examined. | |
889 | ||
890 | ||
e0d19036 NB |
891 | .SH MONITOR MODE |
892 | ||
cd29a5c8 NB |
893 | .HP 12 |
894 | Usage: | |
e0d19036 NB |
895 | .B mdadm --monitor |
896 | .I options... devices... | |
897 | ||
cd29a5c8 | 898 | .PP |
e0d19036 NB |
899 | This usage causes |
900 | .B mdadm | |
901 | to periodically poll a number of md arrays and to report on any events | |
902 | noticed. | |
903 | .B mdadm | |
904 | will never exit once it decides that there are arrays to be checked, | |
905 | so it should normally be run in the background. | |
906 | ||
2d465520 NB |
907 | As well as reporting events, |
908 | .B mdadm | |
909 | may move a spare drive from one array to another if they are in the | |
910 | same | |
911 | .B spare-group | |
912 | and if the destination array has a failed drive but not spares. | |
913 | ||
e0d19036 NB |
914 | If any devices are listed on the command line, |
915 | .B mdadm | |
916 | will only monitor those devices. Otherwise all arrays listed in the | |
917 | configuration file will be monitored. Further, if | |
918 | .B --scan | |
919 | is given, then any other md devices that appear in | |
920 | .B /proc/mdstat | |
921 | will also be monitored. | |
922 | ||
923 | The result of monitoring the arrays is the generation of events. | |
bd526cee | 924 | These events are passed to a separate program (if specified) and may |
2d465520 | 925 | be mailed to a given E-mail address. |
e0d19036 | 926 | |
bd526cee NB |
927 | When passing event to program, the program is run once for each event |
928 | and is given 2 or 3 command-line arguements. The first is the | |
929 | name of the event (see below). The second is the name of the | |
930 | md device which is affected, and the third is the name of a related | |
931 | device if relevant, such as a component device that has failed. | |
cd29a5c8 NB |
932 | |
933 | If | |
934 | .B --scan | |
e0d19036 NB |
935 | is given, then a program or an E-mail address must be specified on the |
936 | command line or in the config file. If neither are available, then | |
937 | .B mdadm | |
938 | will not monitor anything. | |
939 | Without | |
cd29a5c8 | 940 | .B --scan |
e0d19036 | 941 | .B mdadm |
2d465520 | 942 | will continue monitoring as long as something was found to monitor. If |
e0d19036 NB |
943 | no program or email is given, then each event is reported to |
944 | .BR stdout . | |
cd29a5c8 | 945 | |
e0d19036 NB |
946 | The different events are: |
947 | ||
948 | .RS 4 | |
949 | .TP | |
950 | .B DeviceDisappeared | |
2d465520 | 951 | An md array which previously was configured appears to no longer be |
e0d19036 NB |
952 | configured. |
953 | ||
954 | .TP | |
955 | .B RebuildStarted | |
956 | An md array started reconstruction. | |
957 | ||
958 | .TP | |
959 | .BI Rebuild NN | |
960 | Where | |
961 | .I NN | |
962 | is 20, 40, 60, or 80, this indicates that rebuild has passed that many | |
963 | percentage of the total. | |
964 | ||
98c6faba NB |
965 | .TP |
966 | .B RebuildFinished | |
967 | An md array that was rebuilding, isn't any more, either because it | |
968 | finished normally or was aborted. | |
969 | ||
e0d19036 NB |
970 | .TP |
971 | .B Fail | |
972 | An active component device of an array has been marked as faulty. | |
973 | ||
974 | .TP | |
975 | .B FailSpare | |
976 | A spare component device which was being rebuilt to replace a faulty | |
977 | device has failed. | |
978 | ||
979 | .TP | |
980 | .B SpareActive | |
981 | A spare component device which was being rebuilt to replace a faulty | |
982 | device as been successfully rebuild and has been made active. | |
983 | ||
984 | .TP | |
985 | .B NewArray | |
986 | A new md array has been detected in the | |
987 | .B /proc/mdstat | |
988 | file. | |
989 | ||
aa88f531 NB |
990 | .TP |
991 | .B DegradedArray | |
992 | A newly noticed array appears to be degraded. This message is not | |
993 | generated when | |
994 | .I mdadm | |
995 | notices a drive failure which causes degradation, but only when | |
996 | .I mdadm | |
997 | notices that an array is degraded when it first sees the array. | |
998 | ||
e0d19036 NB |
999 | .TP |
1000 | .B MoveSpare | |
1001 | A spare drive has been moved from one array in a | |
1002 | .B spare-group | |
1003 | to another to allow a failed drive to be replaced. | |
1004 | ||
98c6faba NB |
1005 | .TP |
1006 | .B TestMessage | |
1007 | An array was found at startup, and the | |
1008 | .B --test | |
1009 | flag was given. | |
e0d19036 NB |
1010 | .RE |
1011 | ||
1012 | Only | |
98c6faba NB |
1013 | .B Fail , |
1014 | .B FailSpare , | |
1015 | .B DegradedArray , | |
e0d19036 | 1016 | and |
98c6faba | 1017 | .B TestMessage |
e0d19036 NB |
1018 | cause Email to be sent. All events cause the program to be run. |
1019 | The program is run with two or three arguments, they being the event | |
1020 | name, the array device and possibly a second device. | |
1021 | ||
1022 | Each event has an associated array device (e.g. | |
1023 | .BR /dev/md1 ) | |
1024 | and possibly a second device. For | |
1025 | .BR Fail , | |
1026 | .BR FailSpare , | |
1027 | and | |
1028 | .B SpareActive | |
1029 | the second device is the relevant component device. | |
1030 | For | |
1031 | .B MoveSpare | |
1032 | the second device is the array that the spare was moved from. | |
1033 | ||
1034 | For | |
1035 | .B mdadm | |
1036 | to move spares from one array to another, the different arrays need to | |
1037 | be labelled with the same | |
1038 | .B spare-group | |
1039 | in the configuration file. The | |
1040 | .B spare-group | |
1041 | name can be any string. It is only necessary that different spare | |
2d465520 | 1042 | groups use different names. |
e0d19036 NB |
1043 | |
1044 | When | |
9a9dab36 | 1045 | .B mdadm |
e0d19036 NB |
1046 | detects that an array which is in a spare group has fewer active |
1047 | devices than necessary for the complete array, and has no spare | |
1048 | devices, it will look for another array in the same spare group that | |
1049 | has a full complement of working drive and a spare. It will then | |
1050 | attempt to remove the spare from the second drive and add it to the | |
1051 | first. | |
1052 | If the removal succeeds but the adding fails, then it is added back to | |
1053 | the original array. | |
1054 | ||
dd0781e5 NB |
1055 | .SH GROW MODE |
1056 | The GROW mode is used for changing the size or shape of an active | |
1057 | array. | |
1058 | For this to work, the kernel must support the necessary change. | |
1059 | Various types of growth may be added during 2.6 development, possibly | |
1060 | including restructuring a raid5 array to have more active devices. | |
1061 | ||
1062 | Currently the only support available is to change the "size" attribute | |
1063 | for arrays with redundancy, and the raid-disks attribute of RAID1 | |
1064 | arrays. | |
1065 | ||
1066 | Normally when an array is build the "size" it taken from the smallest | |
1067 | of the drives. If all the small drives in an arrays are, one at a | |
1068 | time, removed and replaced with larger drives, then you could have an | |
1069 | array of large drives with only a small amount used. In this | |
1070 | situation, changing the "size" with "GROW" mode will allow the extra | |
1071 | space to start being used. If the size is increased in this way, a | |
1072 | "resync" process will start to make sure the new parts of the array | |
1073 | are synchronised. | |
1074 | ||
1075 | Note that when an array changes size, any filesystem that may be | |
1076 | stored in the array will not automatically grow to use the space. The | |
1077 | filesystem will need to be explicitly told to use the extra space. | |
1078 | ||
1079 | A RAID1 array can work with any number of devices from 1 upwards | |
1080 | (though 1 is not very useful). There may be times which you want to | |
1081 | increase or decrease the number of active devices. Note that this is | |
1082 | different to hot-add or hot-remove which changes the number of | |
1083 | inactive devices. | |
1084 | ||
1085 | When reducing the number of devices in a RAID1 array, the slots which | |
1086 | are to be removed from the array must already be vacant. That is, the | |
1087 | devices that which were in those slots must be failed and removed. | |
1088 | ||
1089 | When the number of devices is increased, any hot spares that are | |
1090 | present may be activated immediately. | |
1091 | ||
2d465520 NB |
1092 | .SH EXAMPLES |
1093 | ||
5787fa49 | 1094 | .B " mdadm --query /dev/name-of-device" |
2d465520 | 1095 | .br |
5787fa49 NB |
1096 | This will find out if a given device is a raid array, or is part of |
1097 | one, and will provide brief information about the device. | |
2d465520 | 1098 | |
5787fa49 | 1099 | .B " mdadm --assemble --scan" |
2d465520 | 1100 | .br |
5787fa49 NB |
1101 | This will assemble and start all arrays listed in the standard confile |
1102 | file. This command will typically go in a system startup file. | |
2d465520 | 1103 | |
2d465520 | 1104 | .B " mdadm --stop --scan" |
5787fa49 NB |
1105 | .br |
1106 | This will shut down all array that can be shut down (i.e. are not | |
1107 | currently in used). This will typically going in a system shutdown script. | |
2d465520 | 1108 | |
5787fa49 | 1109 | .B " mdadm --follow --scan --delay=120" |
2d465520 | 1110 | .br |
5787fa49 NB |
1111 | If (and only if) there is an Email address or program given in the |
1112 | standard config file, then | |
1113 | monitor the status of all arrays listed in that file by | |
1114 | polling them ever 2 minutes. | |
2d465520 | 1115 | |
5787fa49 | 1116 | .B " mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/hd[ac]1" |
2d465520 | 1117 | .br |
5787fa49 | 1118 | Create /dev/md0 as a RAID1 array consisting of /dev/hda1 and /dev/hdc1. |
2d465520 | 1119 | |
2d465520 NB |
1120 | .br |
1121 | .B " echo 'DEVICE /dev/hd*[0-9] /dev/sd*[0-9]' > mdadm.conf" | |
1122 | .br | |
1123 | .B " mdadm --detail --scan >> mdadm.conf" | |
1124 | .br | |
5787fa49 NB |
1125 | This will create a prototype config file that describes currently |
1126 | active arrays that are known to be made from partitions of IDE or SCSI drives. | |
2d465520 NB |
1127 | This file should be reviewed before being used as it may |
1128 | contain unwanted detail. | |
1129 | ||
2d465520 NB |
1130 | .B " echo 'DEVICE /dev/hd[a-z] /dev/sd*[a-z]' > mdadm.conf" |
1131 | .br | |
5787fa49 NB |
1132 | .B " mdadm --examine --scan --config=mdadm.conf >> mdadm.conf" |
1133 | .ber | |
1134 | This will find what arrays could be assembled from existign IDE and | |
1135 | SCSI whole drives (not partitions) and store the information is the | |
1136 | format of a config file. | |
2d465520 NB |
1137 | This file is very likely to contain unwanted detail, particularly |
1138 | the | |
1139 | .B devices= | |
5787fa49 NB |
1140 | entries. It should be reviewed and edited before being used as an |
1141 | actual config file. | |
2d465520 | 1142 | |
5787fa49 | 1143 | .B " mdadm --examine --brief --scan --config=partitions" |
2d465520 | 1144 | .br |
5787fa49 NB |
1145 | .B " mdadm -Ebsc partitions" |
1146 | .br | |
1147 | Create a list of devices by reading | |
1148 | .BR /proc/partitions , | |
1149 | scan these for RAID superblocks, and printout a brief listing of all | |
1150 | that was found. | |
2d465520 | 1151 | |
5787fa49 | 1152 | .B " mdadm -Ac partitions -m 0 /dev/md0" |
2d465520 | 1153 | .br |
5787fa49 NB |
1154 | Scan all partitions and devices listed in |
1155 | .BR /proc/partitions | |
1156 | and assemble | |
1157 | .B /dev/md0 | |
1158 | out of all such devices with a RAID superblock with a minor number of 0. | |
2d465520 | 1159 | |
d013a55e NB |
1160 | .B " mdadm --monitor --scan --daemonise > /var/run/mdadm" |
1161 | .br | |
1162 | If config file contains a mail address or alert program, run mdadm in | |
1163 | the background in monitor mode monitoring all md devices. Also write | |
1164 | pid of mdadm daemon to | |
1165 | .BR /var/run/mdadm . | |
1166 | ||
5787fa49 | 1167 | .B " mdadm --create --help" |
2d465520 | 1168 | .br |
5787fa49 | 1169 | Providew help about the Create mode. |
2d465520 | 1170 | |
5787fa49 NB |
1171 | .B " mdadm --config --help" |
1172 | .br | |
1173 | Provide help about the format of the config file. | |
2d465520 | 1174 | |
5787fa49 NB |
1175 | .B " mdadm --help" |
1176 | .br | |
1177 | Provide general help. | |
cd29a5c8 | 1178 | |
cd29a5c8 NB |
1179 | |
1180 | .SH FILES | |
1181 | ||
1182 | .SS /proc/mdstat | |
1183 | ||
1184 | If you're using the | |
1185 | .B /proc | |
1186 | filesystem, | |
1187 | .B /proc/mdstat | |
2d465520 NB |
1188 | lists all active md devices with information about them. |
1189 | .B mdadm | |
1190 | uses this to find arrays when | |
1191 | .B --scan | |
1192 | is given in Misc mode, and to monitor array reconstruction | |
1193 | on Monitor mode. | |
1194 | ||
cd29a5c8 | 1195 | |
9a9dab36 | 1196 | .SS /etc/mdadm.conf |
cd29a5c8 | 1197 | |
11a3e71d NB |
1198 | The config file lists which devices may be scanned to see if |
1199 | they contain MD super block, and gives identifying information | |
1200 | (e.g. UUID) about known MD arrays. See | |
1201 | .BR mdadm.conf (5) | |
1202 | for more details. | |
cd29a5c8 | 1203 | |
52826846 | 1204 | |
2d465520 NB |
1205 | .SH NOTE |
1206 | .B mdadm | |
1207 | was previously known as | |
1208 | .BR mdctl . | |
1209 | ||
52826846 | 1210 | .SH SEE ALSO |
cd29a5c8 NB |
1211 | For information on the various levels of |
1212 | RAID, check out: | |
1213 | ||
1214 | .IP | |
1215 | .UR http://ostenfeld.dk/~jakob/Software-RAID.HOWTO/ | |
1216 | http://ostenfeld.dk/~jakob/Software-RAID.HOWTO/ | |
1217 | .UE | |
1218 | .PP | |
1219 | for new releases of the RAID driver check out: | |
1220 | ||
1221 | .IP | |
1222 | .UR ftp://ftp.kernel.org/pub/linux/kernel/people/mingo/raid-patches | |
1223 | ftp://ftp.kernel.org/pub/linux/kernel/people/mingo/raid-patches | |
1224 | .UE | |
1225 | .PP | |
1226 | or | |
1227 | .IP | |
1228 | .UR http://www.cse.unsw.edu.au/~neilb/patches/linux-stable/ | |
1229 | http://www.cse.unsw.edu.au/~neilb/patches/linux-stable/ | |
1230 | .URk | |
1231 | .PP | |
56eb10c0 NB |
1232 | .BR mdadm.conf (5), |
1233 | .BR md (4). | |
1234 | .PP | |
52826846 NB |
1235 | .IR raidtab (5), |
1236 | .IR raid0run (8), | |
1237 | .IR raidstop (8), | |
1238 | .IR mkraid (8) |