Any word that beings with a hash sign (#) starts a comment and that
word together with the remainder of the line is ignored.
+Spaces can be included in a word using quotation characters. Either
+single quotes
+.RB ( ' )
+or double quotes (\fB"\fP)
+may be used. All the characters from one quotation character to
+next identical character are protected and will not be used to
+separate words to start new quoted strings. To include a single quote
+it must be between double quotes. To include a double quote it must
+be between single quotes.
+
Any line that starts with white space (space or tab) is treated as
though it were a continuation of the previous line.
Alternatively, a
.B device
-line can contain either of both of the words
+line can contain either or both of the words
.B containers
and
.BR partitions .
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
+to assemble the array. Note that the devices
listed there must also be listed on a DEVICE line.
.TP
.B level=
-The value is a raid level. This is not normally used to
+The value is a RAID level. This is not normally used to
identify an array, but is supported so that the output of
.B "mdadm \-\-examine \-\-scan"
.B \-\-scan
option). There should only be one
.B MAILADDR
-line and it should have only one address.
-
+line and it should have only one address. Any subsequent addresses
+are silently ignored.
.TP
.B MAILFROM
.B CREATE
The
.B create
-line gives default values to be used when creating arrays and device entries for
-arrays.
+line gives default values to be used when creating arrays, new members
+of arrays, and device entries for arrays.
These include:
.RS 4
Give
.B symlinks=no
to suppress this symlink creation.
+
+.TP
+.B names=yes
+Since Linux 2.6.29 it has been possible to create
+.B md
+devices with a name like
+.B md_home
+rather than just a number, like
+.BR md3 .
+.I mdadm
+will use the numeric alternative by default as other tools that interact
+with md arrays may expect only numbers.
+If
+.B names=yes
+is given in
+.I mdadm.conf
+then
+.I mdadm
+will use a name when appropriate.
+If
+.B names=no
+is given, then non-numeric
+.I md
+device names will not be used even if the default changes in a future
+release of
+.IR mdadm .
+
+.TP
+.B bbl=no
+By default,
+.I mdadm
+will reserve space for a bad block list (bbl) on all devices
+included in or added to any array that supports them. Setting
+.B bbl=no
+will prevent this, so newly added devices will not have a bad
+block log.
.RE
.TP
.B \-\-homehost=
option to mdadm. There should normally be only one other word on the line.
It should either be a host name, or one of the special words
-.B <system>
+.BR <system>,
+.B <none>
and
.BR <ignore> .
If
.B <system>
is given, then the
.BR gethostname ( 2 )
-systemcall is used to get the host name.
+systemcall is used to get the host name. This is the default.
If
.B <ignore>
used when creating arrays. This is the only case when there can be
more that one other word on the
.B HOMEHOST
-line.
+line. If there are other words, or other
+.B HOMEHOST
+lines, they are silently ignored.
+
+If
+.B <none>
+is given, then the default of using
+.BR gethostname ( 2 )
+is over-ridden and no homehost name is assumed.
When arrays are created, this host name will be stored in the
metadata. When arrays are assembled using auto-assembly, arrays which
.BR ddf ,
.BR imsm .
+.B AUTO
+should be given at most once. Subsequent lines are silently ignored.
+Thus an earlier config file in a config directory will over-ride
+the setting in a later config file.
+
.TP
.B POLICY
-Allows to specify what automatic behavior is allowed on devices newly
-appearing in the system and provides a way of marking spares that can
-be moved to other array as well as the migration domains.
+This is used to specify what automatic behavior is allowed on devices
+newly appearing in the system and provides a way of marking spares that can
+be moved to other arrays as well as the migration domains.
.I Domain
can be defined through
.I policy
line by specifying a domain name for a number of paths from
.BR /dev/disk/by-path/ .
-A device may belong to several domains. Domain of an array is a union
-of domains of all devices in that array. A spare can be automatically
+A device may belong to several domains. The domain of an array is a union
+of domains of all devices in that array. A spare can be automatically
moved from one array to another if the set of the destination array's
.I domains
contains all the
To update hot plug configuration it is necessary to execute
.B mdadm \-\-udev\-rules
-command after changing config file
+command after changing the config file
-Key words used in
+Key words used in the
.I POLICY
-line and supported values:
+line and supported values are:
.RS 7
.TP
file glob matching anything from
.B /dev/disk/by-path
.TP
+.B type=
+either
+.B disk
+or
+.BR part .
+.TP
.B action=
include, re-add, spare, spare-same-slot, or force-spare
+.TP
+.B auto=
+yes, no, or homehost.
.P
The
.I action
item determines the automatic behavior allowed for devices matching the
.I path
-in the same line. If a device matches several lines with different
+and
+.I type
+in the same line. If a device matches several lines with different
.I actions
then the most permissive will apply. The ordering of policy lines
is irrelevant to the end result.
.B include
allows adding a disk to an array if metadata on that disk matches that array
.TP
-.B re-add
-will include device in the array if it appears to be a current member
-or a member that was recently removed
+.B re\-add
+will include the device in the array if it appears to be a current member
+or a member that was recently removed and the array has a
+write-intent-bitmap to allow the
+.B re\-add
+functionality.
.TP
.B spare
-as above and additionally: if the device is bare it will
-become a spare (for metadata the same line)
+as above and additionally: if the device is bare it can
+become a spare if there is any array that it is a candidate for based
+on domains and metadata.
.TP
.B spare\-same\-slot
as above and additionally if given slot was used by an array that went
degraded recently and the device plugged in has no metadata then it will
be automatically added to that array (or it's container)
.TP
-.B force-spare
+.B force\-spare
as above and the disk will become a spare in remaining cases
.RE
.br
auto=part
.br
+# The name of this array contains a space.
+.br
+ARRAY /dev/md9 name='Data Storage'
+.sp
POLICY domain=domain1 metadata=imsm path=pci-0000:00:1f.2-scsi-*
.br
action=spare
.br
HOMEHOST <system>
.br
-AUTO +1.x homehost -all
+AUTO +1.x homehost \-all
.SH SEE ALSO
.BR mdadm (8),
.BR md (4).
-
projects / thirdparty / mdadm.git / blobdiff