X-Git-Url: http://git.ipfire.org/?a=blobdiff_plain;f=mdadm.8;h=f0381b6914b9555b1bb73d0656c14ce4d42017aa;hb=ec9688ca701adbe8b0dda032d6993c695f24091f;hp=b0aeaacdb404367153be15b34c58038a57622aab;hpb=54bad3644f4ea8132a789e827d05d2e712b4f547;p=thirdparty%2Fmdadm.git diff --git a/mdadm.8 b/mdadm.8 index b0aeaacd..f0381b69 100644 --- a/mdadm.8 +++ b/mdadm.8 @@ -1,15 +1,15 @@ .\" -*- nroff -*- -''' Copyright Neil Brown and others. -''' This program is free software; you can redistribute it and/or modify -''' it under the terms of the GNU General Public License as published by -''' the Free Software Foundation; either version 2 of the License, or -''' (at your option) any later version. -''' See file COPYING in distribution for details. -.TH MDADM 8 "" v2.6.1 +.\" Copyright Neil Brown and others. +.\" This program is free software; you can redistribute it and/or modify +.\" it under the terms of the GNU General Public License as published by +.\" the Free Software Foundation; either version 2 of the License, or +.\" (at your option) any later version. +.\" See file COPYING in distribution for details. +.TH MDADM 8 "" v2.6.7 .SH NAME mdadm \- manage MD devices .I aka -Linux Software Raid. +Linux Software RAID .SH SYNOPSIS @@ -43,55 +43,54 @@ and .B MULTIPATH is not a Software RAID mechanism, but does involve -multiple devices. For -.B MULTIPATH +multiple devices: each device is a path to one common physical storage device. .B FAULTY is also not true RAID, and it only involves one device. It provides a layer over a true device that can be used to inject faults. -'''.B mdadm -'''is a program that can be used to create, manage, and monitor -'''MD devices. As -'''such it provides a similar set of functionality to the -'''.B raidtools -'''packages. -'''The key differences between -'''.B mdadm -'''and -'''.B raidtools -'''are: -'''.IP \(bu 4 -'''.B mdadm -'''is a single program and not a collection of programs. -'''.IP \(bu 4 -'''.B mdadm -'''can perform (almost) all of its functions without having a -'''configuration file and does not use one by default. Also -'''.B mdadm -'''helps with management of the configuration -'''file. -'''.IP \(bu 4 -'''.B mdadm -'''can provide information about your arrays (through Query, Detail, and Examine) -'''that -'''.B raidtools -'''cannot. -'''.P -'''.I mdadm -'''does not use -'''.IR /etc/raidtab , -'''the -'''.B raidtools -'''configuration file, at all. It has a different configuration file -'''with a different format and a different purpose. +.\".B mdadm +.\"is a program that can be used to create, manage, and monitor +.\"MD devices. As +.\"such it provides a similar set of functionality to the +.\".B raidtools +.\"packages. +.\"The key differences between +.\".B mdadm +.\"and +.\".B raidtools +.\"are: +.\".IP \(bu 4 +.\".B mdadm +.\"is a single program and not a collection of programs. +.\".IP \(bu 4 +.\".B mdadm +.\"can perform (almost) all of its functions without having a +.\"configuration file and does not use one by default. Also +.\".B mdadm +.\"helps with management of the configuration +.\"file. +.\".IP \(bu 4 +.\".B mdadm +.\"can provide information about your arrays (through Query, Detail, and Examine) +.\"that +.\".B raidtools +.\"cannot. +.\".P +.\".I mdadm +.\"does not use +.\".IR /etc/raidtab , +.\"the +.\".B raidtools +.\"configuration file, at all. It has a different configuration file +.\"with a different format and a different purpose. .SH MODES mdadm has several major modes of operation: .TP .B Assemble -Assemble the parts of a previously created +Assemble the components of a previously created array into an active array. Components can be explicitly given or can be searched for. .B mdadm @@ -106,7 +105,7 @@ sorts of arrays, .I mdadm cannot differentiate between initial creation and subsequent assembly of an array. It also cannot perform any checks that appropriate -devices have been requested. Because of this, the +components have been requested. Because of this, the .B Build mode should only be used together with a complete understanding of what you are doing. @@ -114,13 +113,13 @@ what you are doing. .TP .B Create Create a new array with per-device superblocks. -'''It can progress -'''in several step create-add-add-run or it can all happen with one command. +.\"It can progress +.\"in several step create-add-add-run or it can all happen with one command. .TP .B "Follow or Monitor" Monitor one or more md devices and act on any state changes. This is -only meaningful for raid1, 4, 5, 6, 10 or multipath arrays as +only meaningful for raid1, 4, 5, 6, 10 or multipath arrays, as only these have interesting state. raid0 or linear never have missing, spare, or failed drives, so there is nothing to monitor. @@ -128,8 +127,8 @@ missing, spare, or failed drives, so there is nothing to monitor. .B "Grow" Grow (or shrink) an array, or otherwise reshape it in some way. Currently supported growth options including changing the active size -of component devices in RAID level 1/4/5/6 and changing the number of -active devices in RAID1/5/6. +of component devices and changing the number of active devices in RAID +levels 1/4/5/6, as well as adding or removing a write-intent bitmap. .TP .B "Incremental Assembly" @@ -151,9 +150,13 @@ adding new spares and removing faulty devices. This is an 'everything else' mode that supports operations on active arrays, operations on component devices such as erasing old superblocks, and information gathering operations. -'''This mode allows operations on independent devices such as examine MD -'''superblocks, erasing old superblocks and stopping active arrays. +.\"This mode allows operations on independent devices such as examine MD +.\"superblocks, erasing old superblocks and stopping active arrays. +.TP +.B Auto-detect +This mode does not act on a specific device or array, but rather it +requests the Linux Kernel to activate any auto-detected arrays. .SH OPTIONS .SH Options for selecting a mode are: @@ -181,9 +184,24 @@ mode. Change the size or shape of an active array. .TP -.BE \-I ", " \-\-incremental +.BR \-I ", " \-\-incremental Add a single device into an appropriate array, and possibly start the array. +.TP +.B \-\-auto-detect +Request that the kernel starts any auto-detected arrays. This can only +work if +.I md +is compiled into the kernel \(em not if it is a module. +Arrays can be auto-detected by the kernel if all the components are in +primary MS-DOS partitions with partition type +.BR FD . +In-kernel autodetect is not recommended for new installations. Using +.I mdadm +to detect and assemble arrays \(em possibly in an +.I initrd +\(em is substantially more flexible and should be preferred. + .P If a device is given before any options, or if the first option is .BR \-\-add , @@ -200,7 +218,7 @@ mode to be assumed. .TP .BR \-h ", " \-\-help Display general help message or, after one of the above options, a -mode specific help message. +mode-specific help message. .TP .B \-\-help\-options @@ -240,17 +258,17 @@ gives an intermediate level of verbosity. .TP .BR \-f ", " \-\-force -Be more forceful about certain operations. See the various modes of +Be more forceful about certain operations. See the various modes for the exact meaning of this option in different contexts. .TP .BR \-c ", " \-\-config= Specify the config file. Default is to use .BR /etc/mdadm.conf , -or if that is missing, then +or if that is missing then .BR /etc/mdadm/mdadm.conf . If the config file given is -.B partitions +.B "partitions" then nothing will be read, but .I mdadm will act as though the config file contained exactly @@ -259,26 +277,25 @@ and will read .B /proc/partitions to find a list of devices to scan. If the word -.B none +.B "none" is given for the config file, then .I mdadm will act as though the config file were empty. .TP .BR \-s ", " \-\-scan -scan config file or +Scan config file or .B /proc/mdstat for missing information. In general, this option gives .B mdadm -permission to get any missing information, like component devices, -array devices, array identities, and alert destination from the -configuration file: -.BR /etc/mdadm.conf . -One exception is MISC mode when using +permission to get any missing information (like component devices, +array devices, array identities, and alert destination) from the +configuration file (see previous option); +one exception is MISC mode when using .B \-\-detail or -.B \-\-stop +.B \-\-stop, in which case .B \-\-scan says to get a list of array devices from @@ -301,11 +318,11 @@ Options are: .RS .IP "0, 0.90, default" Use the original 0.90 format superblock. This format limits arrays to -28 componenet devices and limits component devices of levels 1 and +28 component devices and limits component devices of levels 1 and greater to 2 terabytes. .IP "1, 1.0, 1.1, 1.2" Use the new version-1 format superblock. This has few restrictions. -The different subversion store the superblock at different locations +The different sub-versions store the superblock at different locations on the device, either at the end (for 1.0), at the start (for 1.1) or 4K from the start (for 1.2). .RE @@ -314,13 +331,13 @@ on the device, either at the end (for 1.0), at the start (for 1.1) or .B \-\-homehost= This will override any .B HOMEHOST -setting in the config file and provides the identify of the host which +setting in the config file and provides the identity of the host which should be considered the home for any arrays. When creating an array, the .B homehost will be recorded in the superblock. For version-1 superblocks, it will -be prefixed to the array name. For version-0.90 superblocks part of +be prefixed to the array name. For version-0.90 superblocks, part of the SHA1 hash of the hostname will be stored in the later half of the UUID. @@ -362,7 +379,7 @@ number of spare devices. .TP .BR \-z ", " \-\-size= -Amount (in Kibibytes) of space to use from each drive in RAID1/4/5/6. +Amount (in Kibibytes) of space to use from each drive in RAID level 1/4/5/6. This must be a multiple of the chunk size, and must leave about 128Kb of space at the end of the drive for the RAID superblock. If this is not specified @@ -417,8 +434,8 @@ The layout of the raid5 parity block can be one of The default is .BR left\-symmetric . -When setting the failure mode for -.I faulty +When setting the failure mode for level +.I faulty, the options are: .BR write\-transient ", " wt , .BR read\-transient ", " rt , @@ -428,10 +445,10 @@ the options are: .BR read\-fixable ", " rf , .BR clear ", " flush ", " none . -Each mode can be followed by a number which is used as a period +Each failure mode can be followed by a number, which is used as a period between fault generation. Without a number, the fault is generated once on the first relevant request. With a number, the fault will be -generated after that many request, and will continue to be generated +generated after that many requests, and will continue to be generated every time the period elapses. Multiple failure modes can be current simultaneously by using the @@ -446,24 +463,24 @@ To set the parity with the level of the array ("faulty") must be specified before the fault mode is specified. -Finally, the layout options for RAID10 are one of 'n', 'o' or 'p' followed -by a small number. The default is 'n2'. +Finally, the layout options for RAID10 are one of 'n', 'o' or 'f' followed +by a small number. The default is 'n2'. The supported options are: -.I n +.I 'n' signals 'near' copies. Multiple copies of one data block are at similar offsets in different devices. -.I o +.I 'o' signals 'offset' copies. Rather than the chunks being duplicated within a stripe, whole stripes are duplicated but are rotated by one device so duplicate blocks are on different devices. Thus subsequent copies of a block are in the next drive, and are one chunk further down. -.I f +.I 'f' signals 'far' copies -(multiple copies have very different offsets). See md(4) for more -detail about 'near' and 'far'. +(multiple copies have very different offsets). +See md(4) for more detail about 'near' and 'far'. The number is the number of copies of each datablock. 2 is normal, 3 can be useful. This number can be at most equal to the number of @@ -485,10 +502,10 @@ exist unless .B \-\-force is also given. The same file should be provided when assembling the array. If the word -.B internal +.B "internal" is given, then the bitmap is stored with the metadata on the array, and so is replicated on all devices. If the word -.B none +.B "none" is given with .B \-\-grow mode, then any bitmap that is present is removed. @@ -504,7 +521,7 @@ Storing bitmap files on other filesystems may result in serious problems. Set the chunksize of the bitmap. Each bit corresponds to that many Kilobytes of storage. When using a file based bitmap, the default is to use the smallest -size that is atleast 4 and requires no more than 2^21 chunks. +size that is at-least 4 and requires no more than 2^21 chunks. When using an .B internal bitmap, the chunksize is automatically determined to make best use of @@ -541,7 +558,7 @@ when trying to recover from a major failure as you can be sure that no data will be affected unless you actually write to the array. It can also be used when creating a RAID1 or RAID10 if you want to avoid the initial resync, however this practice \(em while normally safe \(em is not -recommended. Use this ony if you really know what you are doing. +recommended. Use this only if you really know what you are doing. .TP .BR \-\-backup\-file= @@ -678,10 +695,10 @@ will look for super blocks with a minor number of 0. .BR \-N ", " \-\-name= Specify the name of the array to assemble. This must be the name that was specified when creating the array. It must either match -then name stored in the superblock exactly, or it must match +the name stored in the superblock exactly, or it must match with the current .I homehost -is added to the start of the given name. +prefixed to the start of the given name. .TP .BR \-f ", " \-\-force @@ -702,10 +719,10 @@ an attempt will be made to start it anyway. .B \-\-no\-degraded This is the reverse of .B \-\-run -in that it inhibits the started if array unless all expected drives +in that it inhibits the startup of array unless all expected drives are present. This is only needed with -.B \-\-scan -and can be used if you physical connections to devices are +.B \-\-scan, +and can be used if the physical connections to devices are not as reliable as you would like. .TP @@ -840,10 +857,10 @@ update the relevant field in the metadata. .TP .B \-\-auto\-update\-homehost -This flag is only meaning with auto-assembly (see discussion below). +This flag is only meaningful with auto-assembly (see discussion below). In that situation, if no suitable arrays are found for this homehost, .I mdadm -will recan for any arrays at all and will assemble them and update the +will rescan for any arrays at all and will assemble them and update the homehost to match the current host. .SH For Manage mode: @@ -859,11 +876,29 @@ re-add a device that was recently removed from an array. .TP .BR \-r ", " \-\-remove remove listed devices. They must not be active. i.e. they should -be failed or spare devices. +be failed or spare devices. As well as the name of a device file +(e.g. +.BR /dev/sda1 ) +the words +.B failed +and +.B detached +can be given to +.BR \-\-remove . +The first causes all failed device to be removed. The second causes +any device which is no longer connected to the system (i.e an 'open' +returns +.BR ENXIO ) +to be removed. This will only succeed for devices that are spares or +have already been marked as failed. .TP .BR \-f ", " \-\-fail mark listed devices as faulty. +As well as the name of a device file, the word +.B detached +can be given. This will cause any device that has been detached from +the system to be marked as failed. It can then be removed. .TP .BR \-\-set\-faulty @@ -871,19 +906,19 @@ same as .BR \-\-fail . .P -Each of these options require that the first device list is the array -to be acted upon and the remainder are component devices to be added, -removed, or marked as fault. Several different operations can be +Each of these options require that the first device listed is the array +to be acted upon, and the remainder are component devices to be added, +removed, or marked as faulty. Several different operations can be specified for different devices, e.g. .in +5 mdadm /dev/md0 \-\-add /dev/sda1 \-\-fail /dev/sdb1 \-\-remove /dev/sdb1 .in -5 Each operation applies to all devices listed until the next -operations. +operation. If an array is using a write-intent bitmap, then devices which have been removed can be re-added in a way that avoids a full -reconstruction but instead just updated the blocks that have changed +reconstruction but instead just updates the blocks that have changed since the device was removed. For arrays with persistent metadata (superblocks) this is done automatically. For arrays created with .B \-\-build @@ -891,10 +926,9 @@ mdadm needs to be told that this device we removed recently with .BR \-\-re\-add . Devices can only be removed from an array if they are not in active -use. i.e. that must be spares or failed devices. To remove an active -device, it must be marked as -.B faulty -first. +use, i.e. that must be spares or failed devices. To remove an active +device, it must first be marked as +.B faulty. .SH For Misc mode: @@ -912,7 +946,9 @@ Print detail of one or more md devices. .TP .BR \-Y ", " \-\-export When used with -.BR \-\-detail , +.B \-\-detail +or +.BR \-\-examine , output will be formatted as .B key=value pairs for easy import into the environment. @@ -935,6 +971,8 @@ the right thing, then the array can be successfully assembled using .TP .BR \-X ", " \-\-examine\-bitmap Report information about a bitmap file. +The argument is either an external bitmap file or an array component +in case of an internal bitmap. .TP .BR \-R ", " \-\-run @@ -1098,14 +1136,15 @@ is not given, then .I mdadm acts as though .B \-\-scan -was given and identify information is extracted from the configuration file. +was given and identity information is extracted from the configuration file. The identity can be given with the .B \-\-uuid option, with the .B \-\-super\-minor -option, can be found in the config file, or will be taken from the -super block on the first component-device listed on the command line. +option, will be taken from the md-device record in the config file, or +will be taken from the super block of the first component-device +listed on the command line. Devices can be given on the .B \-\-assemble @@ -1140,7 +1179,6 @@ intent is clear. i.e. the name must be in a standard form, or the .B \-\-auto option must be given to clarify how and whether the device should be created. - This can be useful for handling partitioned devices (which don't have a stable device number \(em it can change after a reboot) and when using "udev" to manage your @@ -1150,7 +1188,7 @@ initialisation conventions). If the option to "auto" is "mdp" or "part" or (on the command line only) "p", then mdadm will create a partitionable array, using the -first free one that is not in use, and does not already have an entry +first free one that is not in use and does not already have an entry in /dev (apart from numeric /dev/md* entries). If the option to "auto" is "yes" or "md" or (on the command line) @@ -1161,7 +1199,7 @@ It is expected that the "auto" functionality will be used to create device entries with meaningful names such as "/dev/md/home" or "/dev/md/root", rather than names based on the numerical array number. -When using this option to create a partitionable array, the device +When using option "auto" to create a partitionable array, the device files for the first 4 partitions are also created. If a different number is required it can be simply appended to the auto option. e.g. "auto=part8". Partition names are created by appending a digit @@ -1193,7 +1231,7 @@ anything that it finds which is tagged as belonging to the given homehost. This is the only situation where .I mdadm will assemble arrays without being given specific device name or -identify information for the array. +identity information for the array. If .I mdadm @@ -1209,8 +1247,8 @@ so for example If the array uses version-1 metadata, then the .B name from the superblock is used to similarly create a name in -.BR /dev/md . -The name will have any 'host' prefix stripped first. +.BR /dev/md +(the name will have any 'host' prefix stripped first). If .I mdadm @@ -1235,7 +1273,7 @@ devices from one host to another. .HP 12 Usage: .B mdadm \-\-build -.I device +.I md-device .BI \-\-chunk= X .BI \-\-level= Y .BI \-\-raid\-devices= Z @@ -1258,7 +1296,7 @@ once complete. .HP 12 Usage: .B mdadm \-\-create -.I device +.I md-device .BI \-\-chunk= X .BI \-\-level= Y .br @@ -1332,14 +1370,14 @@ recipe for disaster. Also, using when creating a v0.90 array will silently override any .B \-\-homehost= setting. -'''If the -'''.B \-\-size -'''option is given, it is not necessary to list any component-devices in this command. -'''They can be added later, before a -'''.B \-\-run. -'''If no -'''.B \-\-size -'''is given, the apparent size of the smallest drive given is used. +.\"If the +.\".B \-\-size +.\"option is given, it is not necessary to list any component-devices in this command. +.\"They can be added later, before a +.\".B \-\-run. +.\"If no +.\".B \-\-size +.\"is given, the apparent size of the smallest drive given is used. The General Management options that are valid with .B \-\-create @@ -1387,14 +1425,14 @@ Usage: MISC mode includes a number of distinct operations that operate on distinct devices. The operations are: .TP -\-\-query +.B \-\-query The device is examined to see if it is (1) an active md array, or (2) a component of an md array. The information discovered is reported. .TP -\-\-detail +.B \-\-detail The device should be an active md device. .B mdadm will display a detailed description of the array. @@ -1408,7 +1446,7 @@ The exit status of .I mdadm will normally be 0 unless .I mdadm -failed to get useful information about the device(s). However if the +failed to get useful information about the device(s); however, if the .B \-\-test option is given, then the exit status will be: .RS @@ -1420,23 +1458,22 @@ The array is functioning normally. The array has at least one failed device. .TP 2 -The array has multiple failed devices and hence is unusable (raid4 or -raid5). +The array has multiple failed devices such that it is unusable. .TP 4 There was an error while trying to get information about the device. .RE .TP -\-\-examine +.B \-\-examine The device should be a component of an md array. .B mdadm will read the md superblock of the device and display the contents. If .B \-\-brief -is given, or +or .B \-\-scan -then multiple devices that are components of the one array +is given, then multiple devices that are components of the one array are grouped together and reported in a single entry suitable for inclusion in .BR /etc/mdadm.conf . @@ -1447,27 +1484,27 @@ without listing any devices will cause all devices listed in the config file to be examined. .TP -\-\-stop +.B \-\-stop The devices should be active md arrays which will be deactivated, as long as they are not currently in use. .TP -\-\-run +.B \-\-run This will fully activate a partially assembled md array. .TP -\-\-readonly +.B \-\-readonly This will mark an active array as read-only, providing that it is not currently being used. .TP -\-\-readwrite +.B \-\-readwrite This will change a .B readonly array back to being read/write. .TP -\-\-scan +.B \-\-scan For all operations except .BR \-\-examine , .B \-\-scan @@ -1515,11 +1552,11 @@ The result of monitoring the arrays is the generation of events. These events are passed to a separate program (if specified) and may be mailed to a given E-mail address. -When passing event to program, the program is run once for each event -and is given 2 or 3 command-line arguments. The first is the -name of the event (see below). The second is the name of the +When passing events to a program, the program is run once for each event, +and is given 2 or 3 command-line arguments: the first is the +name of the event (see below), the second is the name of the md device which is affected, and the third is the name of a related -device if relevant, such as a component device that has failed. +device if relevant (such as a component device that has failed). If .B \-\-scan @@ -1528,7 +1565,7 @@ command line or in the config file. If neither are available, then .B mdadm will not monitor anything. Without -.B \-\-scan +.B \-\-scan, .B mdadm will continue monitoring as long as something was found to monitor. If no program or email is given, then each event is reported to @@ -1576,7 +1613,7 @@ faulty. (syslog priority: Critical) .TP .B FailSpare A spare component device which was being rebuilt to replace a faulty -device has failed. (syslog priority: Critial) +device has failed. (syslog priority: Critical) .TP .B SpareActive @@ -1598,7 +1635,7 @@ generated when notices a drive failure which causes degradation, but only when .I mdadm notices that an array is degraded when it first sees the array. -(syslog priority: Critial) +(syslog priority: Critical) .TP .B MoveSpare @@ -1614,7 +1651,7 @@ If has been told, via the config file, that an array should have a certain number of spare devices, and .I mdadm -detects that it has fewer that this number when it first sees the +detects that it has fewer than this number when it first sees the array, it will report a .B SparesMissing message. @@ -1629,14 +1666,14 @@ flag was given. .RE Only -.B Fail , -.B FailSpare , -.B DegradedArray , -.B SparesMissing , +.B Fail, +.B FailSpare, +.B DegradedArray, +.B SparesMissing and .B TestMessage cause Email to be sent. All events cause the program to be run. -The program is run with two or three arguments, they being the event +The program is run with two or three arguments: the event name, the array device and possibly a second device. Each event has an associated array device (e.g. @@ -1654,16 +1691,16 @@ the second device is the array that the spare was moved from. For .B mdadm to move spares from one array to another, the different arrays need to -be labelled with the same +be labeled with the same .B spare-group in the configuration file. The .B spare-group -name can be any string. It is only necessary that different spare +name can be any string; it is only necessary that different spare groups use different names. When .B mdadm -detects that an array which is in a spare group has fewer active +detects that an array in a spare group has fewer active devices than necessary for the complete array, and has no spare devices, it will look for another array in the same spare group that has a full complement of working drive and a spare. It will then @@ -1686,7 +1723,7 @@ for RAID1, RAID5 and RAID6. .IP \(bu 4 increase the "raid-disks" attribute of RAID1, RAID5, and RAID6. .IP \(bu 4 -add a write-intent bitmap to any array which support these bitmaps, or +add a write-intent bitmap to any array which supports these bitmaps, or remove a write-intent bitmap from such an array. .PP @@ -1714,7 +1751,7 @@ inactive devices. When reducing the number of devices in a RAID1 array, the slots which are to be removed from the array must already be vacant. That is, the -devices that which were in those slots must be failed and removed. +devices which were in those slots must be failed and removed. When the number of devices is increased, any hot spares that are present will be activated immediately. @@ -1740,7 +1777,7 @@ to restore the backup and reassemble the array. .SS BITMAP CHANGES A write-intent bitmap can be added to, or removed from, an active -array. Either internal bitmaps, or bitmaps stored in a separate file +array. Either internal bitmaps, or bitmaps stored in a separate file, can be added. Note that if you add a bitmap stored in a file which is in a filesystem that is on the raid array being affected, the system will deadlock. The bitmap must be on a separate filesystem. @@ -1770,7 +1807,7 @@ to be conditionally added to an appropriate array. .I mdadm performs a number of tests to determine if the device is part of an -array, and which array is should be part of. If an appropriate array +array, and which array it should be part of. If an appropriate array is found, or can be created, .I mdadm adds the device to the array and conditionally starts the array. @@ -1782,8 +1819,8 @@ will only add devices to an array which were previously working automatic inclusion of a new drive as a spare in some array. .B "mdadm \-\-incremental" -requires a bug present in all kernels through 2.6.19, to be fixed. -Hopefully this will be fixed in 2.6.20. Alternately apply the patch +requires a bug-fix in all kernels through 2.6.19. +Hopefully, this will be fixed in 2.6.20; alternately, apply the patch which is included with the mdadm source distribution. If .I mdadm detects that this bug is present, it will abort any attempt to use @@ -1827,11 +1864,11 @@ The metadata can match in two ways. Either there is an array listed in .B mdadm.conf which identifies the array (either by UUID, by name, by device list, -or by minor-number), the array was created with a +or by minor-number), or the array was created with a .B homehost -specified, and that +specified and that .B homehost -matches that which is given in +matches the one in .B mdadm.conf or on the command line. If @@ -1841,7 +1878,7 @@ current host, the device will be rejected. .IP + .I mdadm -keeps a list of arrays that is has partly assembled in +keeps a list of arrays that it has partially assembled in .B /var/run/mdadm/map (or .B /var/run/mdadm.map @@ -1880,7 +1917,7 @@ devices present for the data to be accessible. For a raid1, that means one device will start the array. For a clean raid5, the array will be started as soon as all but one drive is present. -Note that neither of these approaches is really ideal. If it is can +Note that neither of these approaches is really ideal. If it can be known that all device discovery has completed, then .br .B " mdadm \-IRs" @@ -1901,12 +1938,12 @@ one, and will provide brief information about the device. .B " mdadm \-\-assemble \-\-scan" .br -This will assemble and start all arrays listed in the standard config file +This will assemble and start all arrays listed in the standard config file. This command will typically go in a system startup file. .B " mdadm \-\-stop \-\-scan" .br -This will shut down all array that can be shut down (i.e. are not +This will shut down all arrays that can be shut down (i.e. are not currently in use). This will typically go in a system shutdown script. .B " mdadm \-\-follow \-\-scan \-\-delay=120" @@ -1933,9 +1970,9 @@ contain unwanted detail. .B " echo 'DEVICE /dev/hd[a\-z] /dev/sd*[a\-z]' > mdadm.conf" .br .B " mdadm \-\-examine \-\-scan \-\-config=mdadm.conf >> mdadm.conf" -.ber -This will find what arrays could be assembled from existing IDE and -SCSI whole drives (not partitions) and store the information is the +.br +This will find arrays which could be assembled from existing IDE and +SCSI whole drives (not partitions), and store the information in the format of a config file. This file is very likely to contain unwanted detail, particularly the @@ -1950,7 +1987,7 @@ actual config file. Create a list of devices by reading .BR /proc/partitions , scan these for RAID superblocks, and printout a brief listing of all -that was found. +that were found. .B " mdadm \-Ac partitions \-m 0 /dev/md0" .br @@ -1977,6 +2014,11 @@ appropriate. Rebuild the array map from any current arrays, and then start any that can be started. +.B " mdadm /dev/md4 --fail detached --remove detached" +.br +Any devices which are components of /dev/md4 will be marked as faulty +and then remove from the array. + .B " mdadm \-\-create \-\-help" .br Provide help about the Create mode. @@ -2017,7 +2059,7 @@ for more details. .SS /var/run/mdadm/map When .B \-\-incremental -mode is used. this file gets a list of arrays currently being created. +mode is used, this file gets a list of arrays currently being created. If .B /var/run/mdadm does not exist as a directory, then @@ -2034,7 +2076,7 @@ behaviour when creating device files via the option. The standard names for non-partitioned arrays (the only sort of md -array available in 2.4 and earlier) either of +array available in 2.4 and earlier) are either of .IP /dev/mdNN .br @@ -2042,7 +2084,7 @@ array available in 2.4 and earlier) either of .PP where NN is a number. The standard names for partitionable arrays (as available from 2.6 -onwards) is one of +onwards) are either of .IP /dev/md/dNN .br @@ -2063,26 +2105,28 @@ package, and does not use the configuration file at all. .SH SEE ALSO -For information on the various levels of -RAID, check out: +For further information on mdadm usage, MD and the various levels of +RAID, see: .IP -.UR http://ostenfeld.dk/~jakob/Software\-RAID.HOWTO/ -http://ostenfeld.dk/~jakob/Software\-RAID.HOWTO/ +.UR http://linux-raid.osdl.org/ +http://linux\-raid.osdl.org/ .UE -'''.PP -'''for new releases of the RAID driver check out: -''' -'''.IP -'''.UR ftp://ftp.kernel.org/pub/linux/kernel/people/mingo/raid-patches -'''ftp://ftp.kernel.org/pub/linux/kernel/people/mingo/raid-patches -'''.UE -'''.PP -'''or -'''.IP -'''.UR http://www.cse.unsw.edu.au/~neilb/patches/linux-stable/ -'''http://www.cse.unsw.edu.au/~neilb/patches/linux-stable/ -'''.UE +.PP +(based upon Jakob \(/Ostergaard's Software\-RAID.HOWTO) +.\".PP +.\"for new releases of the RAID driver check out: +.\" +.\".IP +.\".UR ftp://ftp.kernel.org/pub/linux/kernel/people/mingo/raid-patches +.\"ftp://ftp.kernel.org/pub/linux/kernel/people/mingo/raid-patches +.\".UE +.\".PP +.\"or +.\".IP +.\".UR http://www.cse.unsw.edu.au/~neilb/patches/linux-stable/ +.\"http://www.cse.unsw.edu.au/~neilb/patches/linux-stable/ +.\".UE .PP The latest version of .I mdadm