+''' 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.CONF 5
.SH NAME
mdadm.conf \- configuration for management of Software Raid with mdadm
driver in Linux.
.PP
Some common tasks, such as assembling all arrays, can be simplified
-by describing the devices and array in this configuration file.
+by describing the devices and arrays in this configuration file.
.SS SYNTAX
The file should be seen as a collection of words separated by white
space (space, tab, or newline).
Any word that beings with a hash sign (#) starts a comment and that
-word together with the remainder of the line are ignored.
+word together with the remainder of the line is ignored.
-Any line that start with white space (space or tab) is treated as
+Any line that starts with white space (space or tab) is treated as
though it were a continuation of the previous line.
Empty lines are ignored, but otherwise each (non continuation) line
-must start with a keyword as listed below. The key words are case
+must start with a keyword as listed below. The keywords are case
insensitive and can be abbreviated to 3 characters.
The keywords are:
a component of an MD array. When looking for the components of an
array,
.B mdadm
-will scan these devices and no others.
+will scan these devices (or any devices listed on the command line).
The
.B device
Also, there may be several device lines present in the file.
+Alternatively, a
+.B device
+line can contain the word
+.BR partitions .
+This will cause
+.I mdadm
+to read
+.I /proc/partitions
+and include all devices and partitions found there-in.
+.I mdadm
+does not use the names from
+.I /proc/partitions
+but only the major and minor device numbers. It scans
+.I /dev
+to find the name that matches the numbers.
+
+If no DEVICE line is present, then "DEVICE partitions" is assumed.
+
For example:
.IP
DEVICE /dev/hda* /dev/hdc*
DEV /dev/sd*
.br
DEVICE /dev/discs/disc*/disc
+.br
+DEVICE partitions
.TP
.B ARRAY
.BR /dev/md1 .
Subsequent words identify the array, or identify the array as a member
of a group. If multiple identities are given,
-then the array must match ALL identities to be considered a match.
-Each identity word has a tag, and equals sign, and some value.
-The options are:
+then a component device must match ALL identities to be considered a
+match. Each identity word has a tag, and equals sign, and some value.
+The tags are:
.RS 4
.TP
interspersed if desired. This must match the uuid stored in the
superblock.
.TP
+.B name=
+The value should be a simple textual name as was given to
+.I mdadm
+when the array was created. This must match the name stored in the
+superblock on a device for that device to be included in the array.
+Not all superblock-formats support names.
+.TP
.B super-minor=
The value is an integer which indicates the minor number that was
stored in the superblock when the array was created. When an array is
created as /dev/mdX, then the minor number X is stored.
.TP
.B devices=
-The value is a comma separated list of device names. Precisely these
-devices will be used to assemble the array. Note that the devices
+The value is a comma separated list of device names or device name
+patterns.
+Only devices with names which match one entry in the list will be used
+to assemble the array. Note that the devices
listed there must also be listed on a DEVICE line.
.TP
.B level=
can be use directly in the configuration file.
.TP
-.B disks=
-The value is the number of disks in a complete active array. As with
+.B num-devices=
+The value is the number of devices in a complete active array. As with
.B level=
this is mainly for compatibility with the output of
.BR "mdadm --examine --scan" .
+.TP
+.B spares=
+The value is a number of spare devices to expect the array to have.
+.I mdadm --monitor
+will report an array if it is found to have fewer than this number of
+spares when
+.B --monitor
+starts or when
+.B --oneshot
+is used.
+
.TP
.B spare-group=
The value is a textual name for a group of arrays. All arrays with
will, when monitoring the arrays, move a spare drive from one array in
a group to another array in that group if the first array had a failed
or missing drive but no spare.
+
+.TP
+.B auto=
+This option declares to
+.B mdadm
+that it should try to create the device file of the array if it
+doesn't already exist, or exists but with the wrong device number.
+
+The value of this option can be "yes" or "md" to indicate that a
+traditional, non-partitionable md array should be created, or "mdp",
+"part" or "partition" to indicate that a partitionable md array (only
+available in linux 2.6 and later) should be used. This later set can
+also have a number appended to indicate how many partitions to create
+device files for, e.g.
+.BR auto=mdp5 .
+The default is 4.
+
+.TP
+.B bitmap=
+The option specifies a file in which a write-intent bitmap should be
+found. When assembling the array,
+.I mdadm
+will provide this file to the
+.B md
+driver as the bitmap file. This has the same function as the
+.B --bitmap-file
+option to
+.BR --assemble .
+
+.TP
+.B metadata=
+Specify the metadata format that the array has. This is mainly
+recognised for comparability with the output of
+.IR "mdadm -Es" .
+
.RE
.TP
line and it should have only one address.
+.TP
+.B MAILFROM
+The
+.B mailfrom
+line (which can only be abbreviate at leat 5 characters) gives an
+address to appear in the "From" address for alert mails. This can be
+useful if you want to explicitly set a domain, as the default from
+address is "root" with no domain. All words on this line are
+catenated with spaces to form the address.
+
+Note that this value cannot be set via the
+.I mdadm
+commandline. It is only settable via the config file.
+
.TP
.B PROGRAM
The
line and it should be give only one program.
+.TP
+.B CREATE
+The
+.B create
+line gives default values to be used when creating arrays and device entries for
+arrays.
+These include:
+
+.RS 4
+.TP
+.B owner=
+.TP
+.B group=
+These can give user/group ids or names to use instead of system
+defaults (root/wheel or root/disk).
+.TP
+.B mode=
+An octal file mode such as 0660 can be given to override the default
+of 0600.
+.TP
+.B auto=
+This corresponds to the
+.B --auto
+flag to mdadm. Give
+.BR yes ,
+.BR md ,
+.BR mdp ,
+.B part
+- possibly followed by a number of partitions - to indicate how
+missing device entries should be created.
+
+.TP
+.B metadata=
+The name of the metadata format to use if none is explicitly given.
+This can be useful to impose a system-wide default of version-1 superblocks.
+
+.TP
+.B symlinks=no
+Normally when creating devices in
+.B /dev/md/
+.I mdadm
+will create a matching symlink from
+.B /dev/
+with a name starting
+.B md
+or
+.BR md_ .
+Give
+.B symlinked=no
+to suppress this symlink creation.
+.RE
+
+
+.SH EXAMPLE
+DEVICE /dev/sd[bcdjkl]1
+.br
+DEVICE /dev/hda1 /dev/hdb1
+
+# /dev/md0 is known by it's UID.
+.br
+ARRAY /dev/md0 UUID=3aaa0122:29827cfa:5331ad66:ca767371
+.br
+# /dev/md1 contains all devices with a minor number of
+.br
+# 1 in the superblock.
+.br
+ARRAY /dev/md1 superminor=1
+.br
+# /dev/md2 is made from precisey these two devices
+.br
+ARRAY /dev/md2 devices=/dev/hda1,/dev/hdb1
+
+# /dev/md4 and /dev/md5 are a spare-group and spares
+.br
+# can be moved between them
+.br
+ARRAY /dev/md4 uuid=b23f3c6d:aec43a9f:fd65db85:369432df
+.br
+ spare-group=group1
+.br
+ARRAY /dev/md5 uuid=19464854:03f71b1b:e0df2edd:246cc977
+.br
+ spare-group=group1
+.br
+# /dev/md/home is created if need to be a partitionable md array
+.br
+# any spare device number is allocated.
+.br
+ARRAY /dev/md/home UUID=9187a482:5dde19d9:eea3cc4a:d646ab8b
+.br
+ auto=part
+
+MAILADDR root@mydomain.tld
+.br
+PROGRAM /usr/sbin/handle-mdadm-events
+.br
+CREATE group=system mode=0640 auto=part-8
+.br
+HOMEHOST <system>
+
.SH SEE ALSO
.BR mdadm (8),
.BR md (4).
projects / thirdparty / mdadm.git / blobdiff