+++ /dev/null
-mdadm(8) mdadm(8)
-
-
-
-N\bNA\bAM\bME\bE
- mdadm - manage MD devices _\ba_\bk_\ba Linux Software Raid.
-
-
-S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
- m\bmd\bda\bad\bdm\bm _\b[_\bm_\bo_\bd_\be_\b] _\b<_\br_\ba_\bi_\bd_\bd_\be_\bv_\bi_\bc_\be_\b> _\b[_\bo_\bp_\bt_\bi_\bo_\bn_\bs_\b] _\b<_\bs_\bu_\bb_\bd_\be_\bv_\bi_\bc_\be_\bs_\b>
-
-
-D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
- RAID devices are virtual devices created from two or more
- real block devices. This allows multiple devices (typi-
- cally disk drives or partitions there-of) to be combined
- into a single device to hold (for example) a single
- filesystem. Some RAID levels included redundancy and so
- can survive some degree of device failure.
-
- Linux Software RAID devices are implemented through the md
- (Multiple Devices) device driver.
-
- Currently, Linux supports L\bLI\bIN\bNE\bEA\bAR\bR md devices, R\bRA\bAI\bID\bD0\b0 (strip-
- ing), R\bRA\bAI\bID\bD1\b1 (mirroring), R\bRA\bAI\bID\bD4\b4 and R\bRA\bAI\bID\bD5\b5.\b.
-
- Recent kernels (2002) also support a mode known as M\bMU\bUL\bLT\bTI\bI-\b-
- P\bPA\bAT\bTH\bH. m\bmd\bda\bad\bdm\bm does not support MULTIPATH as yet.
-
- m\bmd\bda\bad\bdm\bm 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 r\bra\bai\bid\bdt\bto\boo\bol\bls\bs packages. The key differ-
- ences between m\bmd\bda\bad\bdm\bm and r\bra\bai\bid\bdt\bto\boo\bol\bls\bs are:
-
- +\bo m\bmd\bda\bad\bdm\bm is a single program and not a collection of pro-
- grams.
-
- +\bo m\bmd\bda\bad\bdm\bm can perform (almost) all of its functions with-
- out having a configuration file. Also mdadm helps
- with management of the configuration file.
-
- +\bo m\bmd\bda\bad\bdm\bm can provide information about your arrays
- (through Detail and Examine) that r\bra\bai\bid\bdt\bto\boo\bol\bls\bs cannot.
-
- +\bo r\bra\bai\bid\bdt\bto\boo\bol\bls\bs can manage MULTIPATH devices which m\bmd\bda\bad\bdm\bm
- cannot yet manage.
-
-
-M\bMO\bOD\bDE\bES\bS
- mdadm has 7 major modes of operation:
-
- A\bAs\bss\bse\bem\bmb\bbl\ble\be
- Assemble the parts of a previously created array
- into an active array. Components can be explicitly
- given or can be searched for. m\bmd\bda\bad\bdm\bm checks that
- the components do form a bona fide array, and can,
- on request, fiddle superblock information so as to
- assemble a faulty array.
-
-
- B\bBu\bui\bil\bld\bd Build a legacy array without per-device
- superblocks.
-
-
- C\bCr\bre\bea\bat\bte\be Create a new array with per-device superblocks.
-
-
- D\bDe\bet\bta\bai\bil\bl Display the details of a given md device. Details
- include the RAID level, the number of devices,
- which ones are faulty (if any), and the array UUID.
-
-
- E\bEx\bxa\bam\bmi\bin\bne\be
- Examine a device to see if it is part of an md
- array, and print out the details of that array.
- This mode can also be used to examine a large num-
- ber of devices and to print out a summary of the
- arrays found in a format suitable for the
- m\bmd\bda\bad\bdm\bm.\b.c\bco\bon\bnf\bf configuration file.
-
-
- F\bFo\bol\bll\blo\bow\bw o\bor\br M\bMo\bon\bni\bit\bto\bor\br
- Monitor one or more md devices and act on any state
- changes.
-
-
- M\bMa\ban\bna\bag\bge\be This is for odd bits an pieces like hotadd,
- hotremove, setfaulty, stop, readonly, readwrite.
-
-
-O\bOP\bPT\bTI\bIO\bON\bNS\bS
- Available options are:
-
-
- -\b-A\bA, -\b--\b-a\bas\bss\bse\bem\bmb\bbl\ble\be
- Assemble an existing array.
-
-
- -\b-B\bB, -\b--\b-b\bbu\bui\bil\bld\bd
- Build a legacy array without superblocks.
-
-
- -\b-C\bC, -\b--\b-c\bcr\bre\bea\bat\bte\be
- Create a new array.
-
-
- -\b-D\bD, -\b--\b-d\bde\bet\bta\bai\bil\bl
- Print detail of one or more md devices.
-
-
- -\b-E\bE, -\b--\b-e\bex\bxa\bam\bmi\bin\bne\be
- Print content of md superblock on device(s).
-
-
- -\b-F\bF, -\b--\b-f\bfo\bol\bll\blo\bow\bw, -\b--\b-m\bmo\bon\bni\bit\bto\bor\br
- Select M\bMo\bon\bni\bit\bto\bor\br mode.
-
-
- -\b-h\bh, -\b--\b-h\bhe\bel\blp\bp
- Display help message or, after above option, mode
- specific help message.
-
-
- -\b-V\bV, -\b--\b-v\bve\ber\brs\bsi\bio\bon\bn
- Print version information for mdadm.
-
-
- -\b-v\bv, -\b--\b-v\bve\ber\brb\bbo\bos\bse\be
- Be more verbose about what is happening.
-
-
- -\b-b\bb, -\b--\b-b\bbr\bri\bie\bef\bf
- Be less verbose. This is used with -\b--\b-d\bde\bet\bta\bai\bil\bl and
- -\b--\b-e\bex\bxa\bam\bmi\bin\bne\be.
-
-
-F\bFo\bor\br c\bcr\bre\bea\bat\bte\be o\bor\br b\bbu\bui\bil\bld\bd:\b:
- -\b-c\bc, -\b--\b-c\bch\bhu\bun\bnk\bk=\b=
- Specify chunk size of kibibytes. The default is
- 64.
-
-
- -\b--\b-r\bro\bou\bun\bnd\bdi\bin\bng\bg=\b=
- Specify rounding factor for linear array (==chunk
- size)
-
-
- -\b-l\bl, -\b--\b-l\ble\bev\bve\bel\bl=\b=
- Set raid level. Options are: linear, raid0, 0,
- stripe, raid1, 1, mirror, raid5, 4, raid5, 5.
- Obviously some of these are synonymous. Only the
- first 4 are valid when Building.
-
-
- -\b-p\bp, -\b--\b-p\bpa\bar\bri\bit\bty\by=\b=
- Set raid5 parity algorithm. Options are:
- {left,right}-{,a}symmetric, la, ra, ls, rs. The
- default is left-symmetric.
-
-
- -\b--\b-l\bla\bay\byo\bou\but\bt=\b=
- same as --parity
-
-
- -\b-n\bn, -\b--\b-r\bra\bai\bid\bd-\b-d\bdi\bis\bsk\bks\bs=\b=
- number of active devices in array.
-
-
- -\b-x\bx, -\b--\b-s\bsp\bpa\bar\bre\be-\b-d\bdi\bis\bsk\bks\bs=\b=
- number of spare (eXtra) disks in initial array.
- Spares can be added and removed later.
-
-
- -\b-z\bz, -\b--\b-s\bsi\biz\bze\be=\b=
- Amount (in Kibibytes) of space to use from each
- drive in RAID1/4/5. 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 (as it normally is not) the
- smallest drive (or partition) sets the size, though
- if there is a variance among the drives of greater
- than 1%, a warning is issued.
-
-
-F\bFo\bor\br a\bas\bss\bse\bem\bmb\bbl\ble\be:\b:
- -\b-u\bu, -\b--\b-u\buu\bui\bid\bd=\b=
- uuid of array to assemble. Devices which don't have
- this uuid are excluded
-
-
- -\b-m\bm, -\b--\b-s\bsu\bup\bpe\ber\br-\b-m\bmi\bin\bno\bor\br=\b=
- Minor number of device that array was created for.
- Devices which don't have this minor number are
- excluded. If you create an array as /dev/md1, then
- all superblock will contain the minor number 1,
- even if the array is later assembled as /dev/md2.
-
-
- -\b-c\bc, -\b--\b-c\bco\bon\bnf\bfi\big\bg=\b=
- config file. Default is /\b/e\bet\btc\bc/\b/m\bmd\bda\bad\bdm\bm.\b.c\bco\bon\bnf\bf.
-
-
- -\b-s\bs, -\b--\b-s\bsc\bca\ban\bn
- scan config file for missing information
-
-
- -\b-f\bf, -\b--\b-f\bfo\bor\brc\bce\be
- Assemble the array even if some superblocks appear
- out-of-date
-
-
- -\b-R\bR, -\b--\b-r\bru\bun\bn
- Attempt to start the array even if fewer drives
- were given than are needed for a full array. Nor-
- mally if not all drives are found and -\b--\b-s\bsc\bca\ban\bn is not
- used, then the array will be assembled but not
- started. With -\b--\b-r\bru\bun\bn an attempt will be made to
- start it anyway.
-
-
-G\bGe\ben\bne\ber\bra\bal\bl m\bma\ban\bna\bag\bge\bem\bme\ben\bnt\bt
- -\b-a\ba, -\b--\b-a\bad\bdd\bd
- hotadd listed devices.
-
-
- -\b-r\br, -\b--\b-r\bre\bem\bmo\bov\bve\be
- remove listed devices. The must not be active.
- i.e. they should be failed or spare devices.
-
-
- -\b-f\bf, -\b--\b-f\bfa\bai\bil\bl
- mark listed devices as faulty.
-
-
- -\b--\b-s\bse\bet\bt-\b-f\bfa\bau\bul\blt\bty\by
- same as --fail.
-
-
- -\b-R\bR, -\b--\b-r\bru\bun\bn
- start a partially built array.
-
-
- -\b-S\bS, -\b--\b-s\bst\bto\bop\bp
- deactivate array, releasing all resources.
-
-
- -\b-o\bo, -\b--\b-r\bre\bea\bad\bdo\bon\bnl\bly\by
- mark array as readonly.
-
-
- -\b-w\bw, -\b--\b-r\bre\bea\bad\bdw\bwr\bri\bit\bte\be
- mark array as readwrite.
-
-
-
-A\bAS\bSS\bSE\bEM\bMB\bBL\bLY\bY M\bMO\bOD\bDE\bE
- Usage: m\bmd\bda\bad\bdm\bm -\b--\b-a\bas\bss\bse\bem\bmb\bbl\ble\be _\bd_\be_\bv_\bi_\bc_\be _\bo_\bp_\bt_\bi_\bo_\bn_\bs_\b._\b._\b.
-
- Usage: m\bmd\bda\bad\bdm\bm -\b--\b-a\bas\bss\bse\bem\bmb\bbl\ble\be -\b--\b-s\bsc\bca\ban\bn _\bo_\bp_\bt_\bi_\bo_\bn_\bs_\b._\b._\b.
-
-
- This usage assembles one or more raid arrays from pre-
- existing components. For each array, mdadm needs to know
- the md device, the identity of the array, and a number of
- sub devices. These can be found in a number of ways.
-
- The md device is either given before -\b--\b-s\bsc\bca\ban\bn or is found
- from the config file. In the latter case, multiple md
- devices can be started with a single mdadm command.
-
- The identity can be given with the -\b--\b-u\buu\bui\bid\bd option, with the
- -\b--\b-s\bsu\bup\bpe\ber\br-\b-m\bmi\bin\bno\bor\br option, can be found in in the config file,
- or will be taken from the super block on the first subde-
- vice listed on the command line.
-
- Devices can be given on the -\b--\b-a\bas\bss\bse\bem\bmb\bbl\ble\be command line or
- from the config file. Only devices which have an md
- superblock which contains the right identity will be con-
- sidered for any device.
-
- The config file is only used if explicitly named with
- -\b--\b-c\bco\bon\bnf\bfi\big\bg or requested with -\b--\b-s\bsc\bca\ban\bn.\b. In the later case,
- /\b/e\bet\btc\bc/\b/m\bmd\bda\bad\bdm\bm.\b.c\bco\bon\bnf\bf is used.
-
- If -\b--\b-s\bsc\bca\ban\bn is not given, then the config file will only be
- used to find the identity of md arrays.
-
- Normally the array will be started after it is assembled.
- However is -\b--\b-s\bsc\bca\ban\bn is not given and insufficient drives
- were lists to start a complete (non-degraded) array, then
- the array is not started (to guard against usage errors).
- To insist that the array be started in this case (as may
- work for RAID1 or RAID5), give the -\b--\b-r\bru\bun\bn flag.
-
-
-
-B\bBU\bUI\bIL\bLD\bD M\bMO\bOD\bDE\bE
- Usage: m\bmd\bda\bad\bdm\bm -\b--\b-b\bbu\bui\bil\bld\bd _\bd_\be_\bv_\bi_\bc_\be -\b--\b-c\bch\bhu\bun\bnk\bk=\b=_\bX -\b--\b-l\ble\bev\bve\bel\bl=\b=_\bY -\b--\b-r\bra\bai\bid\bd-\b-
- d\bdi\bis\bsk\bks\bs=\b=_\bZ _\bd_\be_\bv_\bi_\bc_\be_\bs
-
-
- This usage is similar to -\b--\b-c\bcr\bre\bea\bat\bte\be. The difference is that
- it creates a legacy array without a superblock. With these
- arrays there is no difference between initially creating
- the array and subsequently assembling the array, except
- that hopefully there is useful data there in the second
- case.
-
- The level may only be 0, raid0, or linear. All devices
- must be listed and the array will be started once com-
- plete.
-
-
-C\bCR\bRE\bEA\bAT\bTE\bE M\bMO\bOD\bDE\bE
- Usage: m\bmd\bda\bad\bdm\bm -\b--\b-c\bcr\bre\bea\bat\bte\be _\bd_\be_\bv_\bi_\bc_\be -\b--\b-c\bch\bhu\bun\bnk\bk=\b=_\bX -\b--\b-l\ble\bev\bve\bel\bl=\b=_\bY
- -\b--\b-r\bra\bai\bid\bd-\b-d\bdi\bis\bsk\bks\bs=\b=_\bZ _\bd_\be_\bv_\bi_\bc_\be_\bs
-
-
- This usage will initialise a new md array, associate some
- devices with it, and activate the array.
-
- As devices are added, they are checked to see if they con-
- tain raid superblocks or filesystems. They are also check
- to see if the variance in device size exceeds 1%.
-
- If any discrepancy is found, the array will not automati-
- cally be run, though the presence of a -\b--\b-r\bru\bun\bn can override
- this caution.
-
-
- The General Management options that are valid with --cre-
- ate are:
-
- -\b--\b-r\bru\bun\bn insist of running the array even if some devices
- look like they might be in use.
-
-
- -\b--\b-r\bre\bea\bad\bdo\bon\bnl\bly\by
- start the array readonly - not supported yet.
-
-
-D\bDE\bET\bTA\bAI\bIL\bL M\bMO\bOD\bDE\bE
- Usage: m\bmd\bda\bad\bdm\bm -\b--\b-d\bde\bet\bta\bai\bil\bl [-\b--\b-b\bbr\bri\bie\bef\bf] _\bd_\be_\bv_\bi_\bc_\be _\b._\b._\b.
-
-
- This usage sill print out the details of the given array
- including a list of component devices. To determine names
- for the devices, m\bmd\bda\bad\bdm\bm searches /\b/d\bde\bev\bv for device files with
- the right major and minor numbers.
-
- With -\b--\b-b\bbr\bri\bie\bef\bf m\bmd\bda\bad\bdm\bm prints a single line that identifies
- the level, number of disks, and UUID of the array. This
- line is suitable for inclusion in /\b/e\bet\btc\bc/\b/m\bmd\bda\bad\bdm\bm.\b.c\bco\bon\bnf\bf.
-
-
-E\bEX\bXA\bAM\bMI\bIN\bNE\bE M\bMO\bOD\bDE\bE
- Usage: m\bmd\bda\bad\bdm\bm -\b--\b-e\bex\bxa\bam\bmi\bin\bne\be [-\b--\b-s\bsc\bca\ban\bn] [-\b--\b-b\bbr\bri\bie\bef\bf] _\bd_\be_\bv_\bi_\bc_\be _\b._\b._\b.
-
- This usage will examine some block devices to see if that
- have a valid RAID superblock on them. The information in
- each valid raid superblock will be printed.
-
- If -\b--\b-s\bsc\bca\ban\bn is used, the no devices should be listed, and
- the complete set of devices identified in the configura-
- tion file are checked. -\b--\b-s\bsc\bca\ban\bn implies -\b--\b-b\bbr\bri\bie\bef\bf but this
- implication can be countered by specifying -\b--\b-v\bve\ber\brb\bbo\bos\bse\be.
-
- With -\b--\b-b\bbr\bri\bie\bef\bf m\bmd\bda\bad\bdm\bm will output an config file entry of
- each distinct array that was found. This entry will list
- the UUID, the raid level, and a list of the individual
- devices on which a superblock for that array was found.
- This output will by syntactically suitable for inclusion
- in the configuration file, but should N\bNO\bOT\bT be used blindly.
- Often the array description that you want in the configu-
- ration file is much less specific than that given by m\bmd\bda\bad\bdm\bm
- -\b-B\bBs\bs. For example, you normally do not want to list the
- devices, particularly if they are SCSI devices.
-
-
-
-F\bFI\bIL\bLE\bES\bS
- /\b/p\bpr\bro\boc\bc/\b/m\bmd\bds\bst\bta\bat\bt
- If you're using the /\b/p\bpr\bro\boc\bc filesystem, /\b/p\bpr\bro\boc\bc/\b/m\bmd\bds\bst\bta\bat\bt gives
- you informations about md devices status. This file is
- not currently used by m\bmd\bda\bad\bdm\bm.
-
-
- /\b/e\bet\btc\bc/\b/m\bmd\bda\bad\bdm\bm.\b.c\bco\bon\bnf\bf
- The config file lists which devices may be scanned to see
- if they contain MD super block, and gives identifying
- information (e.g. UUID) about known MD arrays. See
- m\bmd\bda\bad\bdm\bm.\b.c\bco\bon\bnf\bf(5) for more details.
-
-
-
-T\bTO\bOD\bDO\bO
- Finish and document Follow mode.
-
-
-S\bSE\bEE\bE A\bAL\bLS\bSO\bO
- For information on the various levels of RAID, check out:
-
-
- http://ostenfeld.dk/~jakob/Software-RAID.HOWTO/
-
- for new releases of the RAID driver check out:
-
-
- ftp://ftp.kernel.org/pub/linux/kernel/peo-
- ple/mingo/raid-patches
-
- or
-
- http://www.cse.unsw.edu.au/~neilb/patches/linux-
- stable/
-
- m\bmd\bda\bad\bdm\bm.\b.c\bco\bon\bnf\bf(5), m\bmd\bd(4).
-
- _\br_\ba_\bi_\bd_\bt_\ba_\bb(5), _\br_\ba_\bi_\bd_\b0_\br_\bu_\bn(8), _\br_\ba_\bi_\bd_\bs_\bt_\bo_\bp(8), _\bm_\bk_\br_\ba_\bi_\bd(8)
-
-
-
- mdadm(8)
projects / thirdparty / mdadm.git / blobdiff