3 mdadm.conf \- configuration for management of Software Raid with mdadm
9 is a tool for creating, managing, and monitoring RAID devices using the
13 Some common tasks, such as assembling all arrays, can be simplified
14 by describing the devices and arrays in this configuration file.
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 is ignored.
22 Any line that starts with white space (space or tab) is treated as
23 though it were a continuation of the previous line.
25 Empty lines are ignored, but otherwise each (non continuation) line
26 must start with a keyword as listed below. The keywords are case
27 insensitive and can be abbreviated to 3 characters.
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
38 will scan these devices (or any devices listed on the command line).
42 line may contain a number of different devices (separated by spaces)
43 and each device name can contain wild cards as defined by
46 Also, there may be several device lines present in the file.
50 line can contain the word
56 and include all devices and partitions found there-in.
58 does not use the names from
60 but only the major and minor device numbers. It scans
62 to find the name that matches the numbers.
66 DEVICE /dev/hda* /dev/hdc*
70 DEVICE /dev/discs/disc*/disc
76 The ARRAY lines identify actual arrays. The second word on the line
77 should be the name of the device where the array is normally
80 Subsequent words identify the array, or identify the array as a member
81 of a group. If multiple identities are given,
82 then a component device must match ALL identities to be considered a
83 match. Each identity word has a tag, and equals sign, and some value.
89 The value should be a 128 bit uuid in hexadecimal, with punctuation
90 interspersed if desired. This must match the uuid stored in the
94 The value is an integer which indicates the minor number that was
95 stored in the superblock when the array was created. When an array is
96 created as /dev/mdX, then the minor number X is stored.
99 The value is a comma separated list of device names or device name
101 Only devices with names which match one entry in the list will be used
102 to assemble the array. Note that the devices
103 listed there must also be listed on a DEVICE line.
106 The value is a raid level. This is not normally used to
107 identify an array, but is supported so that the output of
109 .B "mdadm --examine --scan"
111 can be use directly in the configuration file.
114 The value is the number of devices in a complete active array. As with
116 this is mainly for compatibility with the output of
118 .BR "mdadm --examine --scan" .
122 The value is a textual name for a group of arrays. All arrays with
125 name are considered to be part of the same group. The significance of
126 a group of arrays is that
128 will, when monitoring the arrays, move a spare drive from one array in
129 a group to another array in that group if the first array had a failed
130 or missing drive but no spare.
134 This option declares to
136 that it should try to create the device file of the array if it
137 doesn't already exist, or exists but with the wrong device number.
139 The value of this option can be "yes" or "md" to indicate that a
140 traditional, non-partitionable md array should be created, or "mdp",
141 "part" or "partition" to indicate that a partitionable md array (only
142 available in linux 2.6 and later) should be used. This later set can
143 also have a number appended to indicate how many partitions to create
144 device files for, e.g.
153 line gives an E-mail address that alerts should be
158 mode (and was given the
160 option). There should only be one
162 line and it should have only one address.
169 line gives the name of a program to be run when
171 detects potentially interesting events on any of the arrays that it
172 is monitoring. This program gets run with two or three arguments, they
173 being the Event, the md device, and possibly the related component
176 There should only be one
178 line and it should be give only one program.
181 DEVICE /dev/sd[bcdjkl]1
183 DEVICE /dev/hda1 /dev/hdb1
185 # /dev/md0 is known by it's UID.
187 ARRAY /dev/md0 UUID=3aaa0122:29827cfa:5331ad66:ca767371
189 # /dev/md1 contains all devices with a minor number of
191 # 1 in the superblock.
193 ARRAY /dev/md1 superminor=1
195 # /dev/md2 is made from precisey these two devices
197 ARRAY /dev/md2 devices=/dev/hda1,/dev/hda2
199 # /dev/md4 and /dev/md5 are a spare-group and spares
201 # can be moved between them
203 ARRAY /dev/md4 uuid=b23f3c6d:aec43a9f:fd65db85:369432df
207 ARRAY /dev/md5 uuid=19464854:03f71b1b:e0df2edd:246cc977
211 # /dev/md/home is created if need to be a partitionable md array
213 # any spare device number is allocated.
215 ARRAY /dev/md/home UUID=9187a482:5dde19d9:eea3cc4a:d646ab8b
219 MAILADDR root@mydomain.tld
221 PROGRAM /usr/sbin/handle-mdadm-events