mdadm.conf.5

   1 .TH MDADM.CONF 5
   2 .SH NAME
   3 mdadm.conf \- configuration for management of Software Raid with mdadm
   4 .SH SYNOPSIS
   5 /etc/mdadm.conf
   6 .SH DESCRIPTION
   7 .PP
   8 .B mdadm
   9 is a tool for creating, managing, and monitoring RAID devices using the
  10 .B md
  11 driver in Linux.
  12 .PP
  13 Some common tasks, such as assembling all arrays, can be simplified
  14 by describing the devices and array in this configuation file.
  15
  16 .SS SYNTAX
  17 The file should be seen as a collection of words separated by white
  18 space (space, tab, or newline).
  19 Any word that beings with a hash sign (#) starts a comment and that
  20 word together with the remainder of the line are ignored.
  21
  22 Any line that start with white space (space or tab) is treated as
  23 though it were a continuation of the previous line.
  24
  25 Empty lines are ignored, but otherwise each (non continuation) line
  26 must start with a keyword as listed below.  The key words are case
  27 insensitve and can be abbreviated to 3 characters.
  28
  29 The keywords are:
  30 .TP
  31 .B DEVICE
  32 A
  33 .B device
  34 line lists the devices (whole devices or partitions) that might contain
  35 a component of an MD array.  When looking for the components of an
  36 array,
  37 .B mdadm
  38 will scan these devices and no others.
  39
  40 The
  41 .B device
  42 line may contain a number of different devices (separated by spaces)
  43 and each device name can contain wild cards as defined by
  44 .BR glob (7).
  45
  46 Also, there may be several device lines present in the file.
  47
  48 For example:
  49 .IP
  50 DEVICE /dev/hda* /dev/hdc*
  51 .br
  52 DEV    /dev/sd*
  53 .br
  54 DEVICE /dev/discs/disc*/disc
  55
  56 .TP
  57 .B ARRAY
  58 The ARRAY lines identify actual arrays.  The second word on the line
  59 should be the name of the device where the array is normally
  60 assembled, such as
  61 .BR  /dev/md1 .
  62 Subsequent words identify the array. If multiple identities are given,
  63 then the array must match ALL identities to be considered a match.
  64 Each identity word has a tag, and equals sign, and some value.
  65 The options are:
  66
  67 .RS 4
  68 .TP
  69 .B uuid=
  70 The value should be a 128 bit uuid in hexadecimal, with punctuation
  71 interspersed if desired.  This must match the uuid stored in the
  72 superblock.
  73 .TP
  74 .B super-minor=
  75 The value is an integer which indicates the minor number that was
  76 stored in the superblock when the array was created. When an array is
  77 created as /dev/mdX, then the minor number X is stored.
  78 .TP
  79 .B devices=
  80 The value is a comma separated list of device names. Precisely these
  81 devices will be used to assemble the array.  Note that the devices
  82 listed there must also be listed on a DEVICE line.
  83 .TP
  84 .B level=
  85 The value is a raid level.  This is not normally used to
  86 identify an array, but is supported so that the output of
  87
  88 .B "mdadm --examine --scan"
  89
  90 can be use directly in the configuration file.
  91 .TP
  92 .B disks=
  93 The value is the number of disks in a complete active array.  As with
  94 .B level=
  95 this is mainly for compatibility with the output of
  96
  97 .BR "mdadm --examine --scan" .
  98 .RE
  99 .SH SEE ALSO
 100 .BR mdadm (8),
 101 .BR md (4).
 102