2 .TH MDADM 8 "" v2.0-devel-3
4 mdadm \- manage MD devices
10 .BI mdadm " [mode] <raiddevice> [options] <component-devices>"
13 RAID devices are virtual devices created from two or more
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.
17 Some RAID levels include redundancy and so can survive some degree of
20 Linux Software RAID devices are implemented through the md (Multiple
21 Devices) device driver.
23 Currently, Linux supports
37 .B MULTIPATH is not a Software RAID mechanism, but does involve
40 each device is a path to one common physical storage device.
42 .B FAULTY is also no true RAID, and it only involves one device. It
43 provides a layer over a true device that can be used to inject faults.
46 is a program that can be used to create, manage, and monitor
48 such it provides a similar set of functionality to the
51 The key differences between
58 is a single program and not a collection of programs.
61 can perform (almost) all of its functions without having a
62 configuration file and does not use one by default. Also
64 helps with management of the configuration
68 can provide information about your arrays (through Query, Detail, and Examine)
78 configuration file, at all. It has a different configuration file
79 with a different format and an different purpose.
82 mdadm has 7 major modes of operation:
85 Assemble the parts of a previously created
86 array into an active array. Components can be explicitly given
87 or can be searched for.
89 checks that the components
90 do form a bona fide array, and can, on request, fiddle superblock
91 information so as to assemble a faulty array.
95 Build an array without per-device superblocks.
99 Create a new array with per-device superblocks.
101 '''in several step create-add-add-run or it can all happen with one command.
105 This is for doing things to specific components of an array such as
106 adding new spares and removing faulty devices.
110 This mode allows operations on independent devices such as examine MD
111 superblocks, erasing old superblocks and stopping active arrays.
114 .B "Follow or Monitor"
115 Monitor one or more md devices and act on any state changes. This is
116 only meaningful for raid1, 4, 5, 6 or multipath arrays as
117 only these have interesting state. raid0 or linear never have
118 missing, spare, or failed drives, so there is nothing to monitor.
122 Grow (or shrink) an array, or otherwise reshape it in some way.
123 Currently supported growth options including changing the active size
124 of componenet devices in RAID level 1/4/5/6 and changing the number of
125 active devices in RAID1.
129 Available options are:
132 .BR -A ", " --assemble
133 Assemble a pre-existing array.
137 Build a legacy array without superblocks.
145 Examine a device to see
146 (1) if it is an md device and (2) if it is a component of an md
148 Information about what is discovered is presented.
152 Print detail of one or more md devices.
155 .BR -E ", " --examine
156 Print content of md superblock on device(s).
159 .BR -F ", " --follow ", " --monitor
166 Change the size or shape of an active array.
169 .BR -X ", " --examine-bitmap
170 Report information about a bitmap file.
174 Display help message or, after above option, mode specific help
179 Display more detailed help about command line parsing and some commonly
183 .BR -V ", " --version
184 Print version information for mdadm.
187 .BR -v ", " --verbose
188 Be more verbose about what is happening. This can be used twice to be
190 This currently only affects
193 .BR "--examine --scan" .
197 Be less verbose. This is used with
205 gives an intermediate level of verbosity.
208 .BR -b ", " --bitmap=
209 Give the name of a bitmap file to use with this array. Can be used
210 with --create (file should not exist) or --assemble (file should
215 Set the Chunksize of the bitmap. Each bit corresponds to that many
216 Kilobytes of storage. Default is 4.
221 Be more forceful about certain operations. See the various modes of
222 the exact meaning of this option in different contexts.
225 .BR -c ", " --config=
226 Specify the config file. Default is
227 .BR /etc/mdadm.conf .
228 If the config file given is
230 then nothing will be read, but
232 will act as though the config file contained exactly
233 .B "DEVICE partitions"
236 to find a list of devices to scan.
239 is given for the config file, then
241 will act as though the config file were empty.
247 for missing information.
248 In general, this option gives
250 permission to get any missing information, like component devices,
251 array devices, array identities, and alert destination from the
253 .BR /etc/mdadm.conf .
254 One exception is MISC mode when using
260 says to get a list of array devices from
264 .B -e ", " --metadata=
265 Declare the style of superblock (raid metadata) to be used. The
266 default is 0.90 for --create, and to guess for other operations.
270 .IP "0, 0.90, default"
271 Use the original 0.90 format superblock. This format limits arrays to
272 28 componenet devices and limits component devices of levels 1 and
273 greater to 2 terabytes.
274 .IP "1, 1.0, 1.1, 1.2"
275 Use the new version-1 format superblock. This has few restrictions.
276 The different subversion store the superblock at different locations
277 on the device, either at the end (for 1.0), at the start (for 1.1) or
278 4K from the start (for 1.2).
281 .SH For create or build:
285 Specify chunk size of kibibytes. The default is 64.
289 Specify rounding factor for linear array (==chunk size)
293 Set raid level. When used with
295 options are: linear, raid0, 0, stripe, raid1, 1, mirror, raid4, 4,
296 raid5, 5, raid6, 6, multipath, mp, fautly. Obviously some of these are synonymous.
300 only linear, raid0, 0, stripe are valid.
303 .BR -p ", " --parity=
304 Set raid5 parity algorithm. Options are:
309 la, ra, ls, rs. The default is left-symmetric.
311 This option is also used to set the failure mode for
329 Each mode can be followed by a number which is used as a period
330 between fault generation. Without a number, the fault is generated
331 once on the first relevant request. With a number, the fault will be
332 generated after that many request, and will continue to be generated
333 every time the period elapses.
335 Multiple failure modes can be current simultaneously by using the
336 "--grow" option to set subsequent failure modes.
338 "clear" or "none" will remove any pending or periodic failure modes,
339 and "flush" will clear any persistant faults.
341 To set the parity with "--grow", the level of the array ("faulty")
342 must be specified before the fault mode is specified.
349 .BR -b ", " --bitmap=
350 Specify a file to store a write-intent bitmap in. The file should not
351 exist unless --force is also given. The same file should be provided
352 when assembling the array.
356 Specifty the chunksize for the bitmap.
359 .BR -n ", " --raid-devices=
360 Specify the number of active devices in the array. This, plus the
361 number of spare devices (see below) must equal the number of
363 (including "\fBmissing\fP" devices)
364 that are listed on the command line for
366 Setting a value of 1 is probably
367 a mistake and so requires that
369 be specified first. A value of 1 will then be allowed for linear,
370 multipath, raid0 and raid1. It is never allowed for raid4 or raid5.
372 This number can only be changed using
374 for RAID1 arrays, and only on kernels which provide necessary support.
377 .BR -x ", " --spare-devices=
378 Specify the number of spare (eXtra) devices in the initial array.
379 Spares can also be added
380 and removed later. The number of component devices listed
381 on the command line must equal the number of raid devices plus the
382 number of spare devices.
387 Amount (in Kibibytes) of space to use from each drive in RAID1/4/5/6.
388 This must be a multiple of the chunk size, and must leave about 128Kb
389 of space at the end of the drive for the RAID superblock.
390 If this is not specified
391 (as it normally is not) the smallest drive (or partition) sets the
392 size, though if there is a variance among the drives of greater than 1%, a warning is
395 This value can be set with
397 for RAID level 1/4/5/6. If the array was created with a size smaller
398 than the currently active drives, the extra space can be accessed
401 The size can be given as
403 which means to choose the largest size that fits all on all current drives.
409 that the array pre-existed and is known to be clean. This is only
410 really useful for Building RAID1 array. Only use this if you really
411 know what you are doing. This is currently only supported for --build.
417 run the array, even if some of the components
418 appear to be active in another array or filesystem. Normally
420 will ask for confirmation before including such components in an
421 array. This option causes that question to be suppressed.
427 accept the geometry and layout specified without question. Normally
429 will not allow creation of an array with only one device, and will try
430 to create a raid5 array with one missing drive (as this makes the
431 initial resync work faster). With
434 will not try to be so clever.
437 .BR -a ", " "--auto{=no,yes,md,mdp,part,p}{NN}"
438 Instruct mdadm to create the device file if needed, possibly allocating
439 an unused minor number. "md" causes a non-partitionable array
440 to be used. "mdp", "part" or "p" causes a partitionable array (2.6 and
441 later) to be used. "yes" requires the named md device to have a
442 'standard' format, and the type and minor number will be determined
443 from this. See DEVICE NAMES below.
445 The argumentment can also come immediately after
450 is also given, then any
452 entries in the config file will over-ride the
454 instruction given on the command line.
456 For partitionable arrays,
458 will create the device file for the whole array and for the first 4
459 partitions. A different number of partitions can be specified at the
460 end of this option (e.g.
462 If the device name ends with a digit, the partition names add a'p',
463 and a number, e.g. "/dev/home1p3". If there is no
464 trailing digit, then the partition names just have a number added,
465 e.g. "/dev/scratch3".
467 If the md device name is in a 'standard' format as described in DEVICE
468 NAMES, then it will be created, if necessary, with the appropriate
469 number based on that name. If the device name is not in one of these
470 formats, then a unused minor number will be allocted. The minor
471 number will be considered unused if there is no active array for that
472 number, and there is no entry in /dev for that number and with a
479 uuid of array to assemble. Devices which don't have this uuid are
483 .BR -m ", " --super-minor=
484 Minor number of device that array was created for. Devices which
485 don't have this minor number are excluded. If you create an array as
486 /dev/md1, then all superblocks will contain the minor number 1, even if
487 the array is later assembled as /dev/md2.
489 Giving the literal word "dev" for
493 to use the minor number of the md device that is being assembled.
497 will look for super blocks with a minor number of 0.
501 Assemble the array even if some superblocks appear out-of-date
505 Attempt to start the array even if fewer drives were given than are
506 needed for a full array. Normally if not all drives are found and
508 is not used, then the array will be assembled but not started.
511 an attempt will be made to start it anyway.
514 .BR -a ", " "--auto{=no,yes,md,mdp,part}"
515 See this option under Create and Build options.
518 .BR -b ", " --bitmap=
519 Specify the bitmap file that was given when the array was created.
522 .BR -U ", " --update=
523 Update the superblock on each device while assembling the array. The
524 argument given to this flag can be one of
534 option will adjust the superblock of an array what was created on a Sparc
535 machine running a patched 2.2 Linux kernel. This kernel got the
536 alignment of part of the superblock wrong. You can use the
537 .B "--examine --sparc2.2"
540 to see what effect this would have.
544 option will update the
546 field on each superblock to match the minor number of the array being
547 assembled. This is not needed on 2.6 and later kernels as they make
548 this adjustment automatically.
552 option will cause the array to be marked
554 meaning that any redundancy in the array (e.g. parity for raid5,
555 copies for raid1) may be incorrect. This will cause the raid system
556 to perform a "resync" pass to make sure that all redundant information
561 option allows arrays to be moved between machines with different
563 When assembling such an array for the first time after a move, giving
564 .B "--update=byteorder"
567 to expect superblocks to have their byteorder reversed, and will
568 correct that order before assembling the array. This is only valid
569 with original (Verion 0.90) superblocks.
573 option will correct the summaries in the superblock. That is the
574 counts of total, working, active, failed, and spare devices.
581 hotadd listed devices.
585 remove listed devices. They must not be active. i.e. they should
586 be failed or spare devices.
590 mark listed devices as faulty.
596 .SH For Examine mode:
600 In an array was created on a 2.2 Linux kernel patched with RAID
601 support, the superblock will have been created incorrectly, or at
602 least incompatibly with 2.4 and later kernels. Using the
606 will fix the superblock before displaying it. If this appears to do
607 the right thing, then the array can be successfully assembled using
608 .BR "--assemble --update=sparc2.2" .
614 start a partially built array.
618 deactivate array, releasing all resources.
621 .BR -o ", " --readonly
622 mark array as readonly.
625 .BR -w ", " --readwrite
626 mark array as readwrite.
630 If the device contains a valid md superblock, the block is
631 over-written with zeros. With
633 the block where the superblock would be is over-written even if it
634 doesn't appear to be valid.
642 is set to reflect the status of the device.
644 .SH For Monitor mode:
647 Give a mail address to send alerts to.
650 .BR -p ", " --program ", " --alert
651 Give a program to be run whenever an event is detected.
655 Give a delay in seconds.
657 polls the md arrays and then waits this many seconds before polling
658 again. The default is 60 seconds.
661 .BR -f ", " --daemonise
664 to run as a background daemon if it decides to monitor anything. This
665 causes it to fork and run in the child, and to disconnect form the
666 terminal. The process id of the child is written to stdout.
669 which will only continue monitoring if a mail address or alert program
670 is found in the config file.
673 .BR -i ", " --pid-file
676 is running in daemon mode, write the pid of the daemon process to
677 the specified file, instead of printing it on standard output.
680 .BR -1 ", " --oneshot
681 Check arrays only once. This will generate
683 events and more significantly
687 .B " mdadm --monitor --scan -1"
689 from a cron script will ensure regular notification of any degraded arrays.
695 alert for every array found at startup. This alert gets mailed and
696 passed to the alert program. This can be used for testing that alert
697 message to get through successfully.
704 .I md-device options-and-component-devices...
707 .B mdadm --assemble --scan
708 .I md-devices-and-options...
711 .B mdadm --assemble --scan
715 This usage assembles one or more raid arrays from pre-existing components.
716 For each array, mdadm needs to know the md device, the identity of the
717 array, and a number of component-devices. These can be found in a number of ways.
719 In the first usage example (without the
721 the first device given is the md device.
722 In the second usage example, all devices listed are treated as md
723 devices and assembly is attempted.
724 In the third (where no devices are listed) all md devices that are
725 listed in the configuration file are assembled.
727 If precisely one device is listed, but
733 was given and identify information is extracted from the configuration file.
735 The identity can be given with the
739 option, can be found in the config file, or will be taken from the
740 super block on the first component-device listed on the command line.
742 Devices can be given on the
744 command line or in the config file. Only devices which have an md
745 superblock which contains the right identity will be considered for
748 The config file is only used if explicitly named with
750 or requested with (a possibly implicit)
758 is not given, then the config file will only be used to find the
759 identity of md arrays.
761 Normally the array will be started after it is assembled. However if
763 is not given and insufficient drives were listed to start a complete
764 (non-degraded) array, then the array is not started (to guard against
765 usage errors). To insist that the array be started in this case (as
766 may work for RAID1, 4, 5 or 6), give the
772 option is given, either on the command line (--auto) or in the
773 configuration file (e.g. auto=part), then
775 will create the md device if necessary or will re-create it if it
776 doesn't look usable as it is.
778 This can be useful for handling partitioned devices (which don't have
779 a stable device number - it can change after a reboot) and when using
780 "udev" to manage your
782 tree (udev cannot handle md devices because of the unusual device
783 initialisation conventions).
785 If the option to "auto" is "mdp" or "part" or (on the command line
786 only) "p", then mdadm will create a partitionable array, using the
787 first free one that is not inuse, and does not already have an entry
788 in /dev (apart from numeric /dev/md* entries).
790 If the option to "auto" is "yes" or "md" or (on the command line)
791 nothing, then mdadm will create a traditional, non-partitionable md
794 It is expected that the "auto" functionality will be used to create
795 device entries with meaningful names such as "/dev/md/home" or
796 "/dev/md/root", rather than names based on the numerical array number.
798 When using this option to create a partitionable array, the device
799 files for the first 4 partitions are also created. If a different
800 number is required it can be simply appended to the auto option.
801 e.g. "auto=part8". Partition names are created by appending a digit
802 string to the device name, with an intervening "_p" if the device name
807 option is also available in Build and Create modes. As those modes do
808 not use a config file, the "auto=" config option does not apply to
819 .BI --raid-devices= Z
823 This usage is similar to
825 The difference is that it creates a legacy array without a superblock. With
826 these arrays there is no difference between initially creating the array and
827 subsequently assembling the array, except that hopefully there is useful
828 data there in the second case.
830 The level may only be 0, raid0, or linear. All devices must be listed
831 and the array will be started once complete.
842 .BI --raid-devices= Z
846 This usage will initialise a new md array, associate some devices with
847 it, and activate the array.
851 option is given (as described in more detail in the section on
852 Assemble mode), then the md device will be created with a suitable
853 device number if necessary.
855 As devices are added, they are checked to see if they contain raid
856 superblocks or filesystems. They are also checked to see if the variance in
857 device size exceeds 1%.
859 If any discrepancy is found, the array will not automatically be run, though
862 can override this caution.
864 To create a "degraded" array in which some devices are missing, simply
865 give the word "\fBmissing\fP"
866 in place of a device name. This will cause
868 to leave the corresponding slot in the array empty.
869 For a RAID4 or RAID5 array at most one slot can be
870 "\fBmissing\fP"; for a RAID6 array at most two slots.
871 For a RAID1 array, only one real device needs to be given. All of the
875 When creating a RAID5 array,
877 will automatically create a degraded array with an extra spare drive.
878 This is because building the spare into a degraded array is in general faster than resyncing
879 the parity on a non-degraded, but not clean, array. This feature can
880 be over-ridden with the
886 '''option is given, it is not necessary to list any component-devices in this command.
887 '''They can be added later, before a
891 '''is given, the apparent size of the smallest drive given is used.
893 The General Management options that are valid with --create are:
896 insist on running the array even if some devices look like they might
901 start the array readonly - not supported yet.
908 .I options... devices...
911 This usage will allow individual devices in an array to be failed,
912 removed or added. It is possible to perform multiple operations with
913 on command. For example:
915 .B " mdadm /dev/md0 -f /dev/hda1 -r /dev/hda1 -a /dev/hda1"
921 and will then remove it from the array and finally add it back
922 in as a spare. However only one md array can be affected by a single
933 MISC mode includes a number of distinct operations that
934 operate on distinct devices. The operations are:
937 The device is examined to see if it is
938 (1) an active md array, or
939 (2) a component of an md array.
940 The information discovered is reported.
944 The device should be an active md device.
946 will display a detailed description of the array.
950 will cause the output to be less detailed and the format to be
951 suitable for inclusion in
952 .BR /etc/mdadm.conf .
955 will normally be 0 unless
957 failed to get useful information about the device(s). However if the
959 option is given, then the exit status will be:
963 The array is functioning normally.
966 The array has at least one failed device.
969 The array has multiple failed devices and hence is unusable (raid4 or
973 There was an error while trying to get information about the device.
978 The device should be a component of an md array.
980 will read the md superblock of the device and display the contents.
985 then multiple devices that are components of the one array
986 are grouped together and reported in a single entry suitable
988 .BR /etc/mdadm.conf .
992 without listing any devices will cause all devices listed in the
993 config file to be examined.
997 The devices should be active md arrays which will be deactivated, as
998 long as they are not currently in use.
1002 This will fully activate a partially assembled md array.
1006 This will mark an active array as read-only, providing that it is
1007 not currently being used.
1013 array back to being read/write.
1017 For all operations except
1020 will cause the operation to be applied to all arrays listed in
1025 causes all devices listed in the config file to be examined.
1033 .I options... devices...
1038 to periodically poll a number of md arrays and to report on any events
1041 will never exit once it decides that there are arrays to be checked,
1042 so it should normally be run in the background.
1044 As well as reporting events,
1046 may move a spare drive from one array to another if they are in the
1049 and if the destination array has a failed drive but not spares.
1051 If any devices are listed on the command line,
1053 will only monitor those devices. Otherwise all arrays listed in the
1054 configuration file will be monitored. Further, if
1056 is given, then any other md devices that appear in
1058 will also be monitored.
1060 The result of monitoring the arrays is the generation of events.
1061 These events are passed to a separate program (if specified) and may
1062 be mailed to a given E-mail address.
1064 When passing event to program, the program is run once for each event
1065 and is given 2 or 3 command-line arguements. The first is the
1066 name of the event (see below). The second is the name of the
1067 md device which is affected, and the third is the name of a related
1068 device if relevant, such as a component device that has failed.
1072 is given, then a program or an E-mail address must be specified on the
1073 command line or in the config file. If neither are available, then
1075 will not monitor anything.
1079 will continue monitoring as long as something was found to monitor. If
1080 no program or email is given, then each event is reported to
1083 The different events are:
1087 .B DeviceDisappeared
1088 An md array which previously was configured appears to no longer be
1093 was told to monitor an array which is RAID0 or Linear, then it will
1095 .B DeviceDisappeared
1096 with the extra information
1098 This is because RAID0 and Linear do not support the device-failed,
1099 hot-spare and resync operations which are monitored.
1103 An md array started reconstruction.
1109 is 20, 40, 60, or 80, this indicates that rebuild has passed that many
1110 percentage of the total.
1114 An md array that was rebuilding, isn't any more, either because it
1115 finished normally or was aborted.
1119 An active component device of an array has been marked as faulty.
1123 A spare component device which was being rebuilt to replace a faulty
1128 A spare component device which was being rebuilt to replace a faulty
1129 device as been successfully rebuild and has been made active.
1133 A new md array has been detected in the
1139 A newly noticed array appears to be degraded. This message is not
1142 notices a drive failure which causes degradation, but only when
1144 notices that an array is degraded when it first sees the array.
1148 A spare drive has been moved from one array in a
1150 to another to allow a failed drive to be replaced.
1156 has been told, via the config file, that an array should have a certain
1157 number of spare devices, and
1159 detects that it has fewer that this number when it first sees the
1160 array, it will report a
1166 An array was found at startup, and the
1177 cause Email to be sent. All events cause the program to be run.
1178 The program is run with two or three arguments, they being the event
1179 name, the array device and possibly a second device.
1181 Each event has an associated array device (e.g.
1183 and possibly a second device. For
1188 the second device is the relevant component device.
1191 the second device is the array that the spare was moved from.
1195 to move spares from one array to another, the different arrays need to
1196 be labelled with the same
1198 in the configuration file. The
1200 name can be any string. It is only necessary that different spare
1201 groups use different names.
1205 detects that an array which is in a spare group has fewer active
1206 devices than necessary for the complete array, and has no spare
1207 devices, it will look for another array in the same spare group that
1208 has a full complement of working drive and a spare. It will then
1209 attempt to remove the spare from the second drive and add it to the
1211 If the removal succeeds but the adding fails, then it is added back to
1215 The GROW mode is used for changing the size or shape of an active
1217 For this to work, the kernel must support the necessary change.
1218 Various types of growth may be added during 2.6 development, possibly
1219 including restructuring a raid5 array to have more active devices.
1221 Currently the only support available is to change the "size" attribute
1222 for arrays with redundancy, and the raid-disks attribute of RAID1
1225 Normally when an array is build the "size" it taken from the smallest
1226 of the drives. If all the small drives in an arrays are, one at a
1227 time, removed and replaced with larger drives, then you could have an
1228 array of large drives with only a small amount used. In this
1229 situation, changing the "size" with "GROW" mode will allow the extra
1230 space to start being used. If the size is increased in this way, a
1231 "resync" process will start to make sure the new parts of the array
1234 Note that when an array changes size, any filesystem that may be
1235 stored in the array will not automatically grow to use the space. The
1236 filesystem will need to be explicitly told to use the extra space.
1238 A RAID1 array can work with any number of devices from 1 upwards
1239 (though 1 is not very useful). There may be times which you want to
1240 increase or decrease the number of active devices. Note that this is
1241 different to hot-add or hot-remove which changes the number of
1244 When reducing the number of devices in a RAID1 array, the slots which
1245 are to be removed from the array must already be vacant. That is, the
1246 devices that which were in those slots must be failed and removed.
1248 When the number of devices is increased, any hot spares that are
1249 present may be activated immediately.
1253 .B " mdadm --query /dev/name-of-device"
1255 This will find out if a given device is a raid array, or is part of
1256 one, and will provide brief information about the device.
1258 .B " mdadm --assemble --scan"
1260 This will assemble and start all arrays listed in the standard confile
1261 file. This command will typically go in a system startup file.
1263 .B " mdadm --stop --scan"
1265 This will shut down all array that can be shut down (i.e. are not
1266 currently in use). This will typically go in a system shutdown script.
1268 .B " mdadm --follow --scan --delay=120"
1270 If (and only if) there is an Email address or program given in the
1271 standard config file, then
1272 monitor the status of all arrays listed in that file by
1273 polling them ever 2 minutes.
1275 .B " mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/hd[ac]1"
1277 Create /dev/md0 as a RAID1 array consisting of /dev/hda1 and /dev/hdc1.
1280 .B " echo 'DEVICE /dev/hd*[0-9] /dev/sd*[0-9]' > mdadm.conf"
1282 .B " mdadm --detail --scan >> mdadm.conf"
1284 This will create a prototype config file that describes currently
1285 active arrays that are known to be made from partitions of IDE or SCSI drives.
1286 This file should be reviewed before being used as it may
1287 contain unwanted detail.
1289 .B " echo 'DEVICE /dev/hd[a-z] /dev/sd*[a-z]' > mdadm.conf"
1291 .B " mdadm --examine --scan --config=mdadm.conf >> mdadm.conf"
1293 This will find what arrays could be assembled from existign IDE and
1294 SCSI whole drives (not partitions) and store the information is the
1295 format of a config file.
1296 This file is very likely to contain unwanted detail, particularly
1299 entries. It should be reviewed and edited before being used as an
1302 .B " mdadm --examine --brief --scan --config=partitions"
1304 .B " mdadm -Ebsc partitions"
1306 Create a list of devices by reading
1307 .BR /proc/partitions ,
1308 scan these for RAID superblocks, and printout a brief listing of all
1311 .B " mdadm -Ac partitions -m 0 /dev/md0"
1313 Scan all partitions and devices listed in
1314 .BR /proc/partitions
1317 out of all such devices with a RAID superblock with a minor number of 0.
1319 .B " mdadm --monitor --scan --daemonise > /var/run/mdadm"
1321 If config file contains a mail address or alert program, run mdadm in
1322 the background in monitor mode monitoring all md devices. Also write
1323 pid of mdadm daemon to
1324 .BR /var/run/mdadm .
1326 .B " mdadm --create --help"
1328 Providew help about the Create mode.
1330 .B " mdadm --config --help"
1332 Provide help about the format of the config file.
1336 Provide general help.
1347 lists all active md devices with information about them.
1349 uses this to find arrays when
1351 is given in Misc mode, and to monitor array reconstruction
1357 The config file lists which devices may be scanned to see if
1358 they contain MD super block, and gives identifying information
1359 (e.g. UUID) about known MD arrays. See
1365 While entries in the /dev directory can have any format you like,
1367 has an understanding of 'standard' formats which it uses to guide its
1368 behaviour when creating device files via the
1372 The standard names for non-partitioned arrays (the only sort of md
1373 array available in 2.4 and earlier) either of
1379 where NN is a number.
1380 The standard names for partitionable arrays (as available from 2.6
1387 Partition numbers should be indicated by added "pMM" to these, thus "/dev/md/d1p2".
1391 was previously known as
1395 For information on the various levels of
1399 .UR http://ostenfeld.dk/~jakob/Software-RAID.HOWTO/
1400 http://ostenfeld.dk/~jakob/Software-RAID.HOWTO/
1403 for new releases of the RAID driver check out:
1406 .UR ftp://ftp.kernel.org/pub/linux/kernel/people/mingo/raid-patches
1407 ftp://ftp.kernel.org/pub/linux/kernel/people/mingo/raid-patches
1412 .UR http://www.cse.unsw.edu.au/~neilb/patches/linux-stable/
1413 http://www.cse.unsw.edu.au/~neilb/patches/linux-stable/
projects / thirdparty / mdadm.git / blob