Check all member devices in enough_fd

[thirdparty/mdadm.git] / mdadm.conf.5

diff --git a/mdadm.conf.5 b/mdadm.conf.5
index 40295bee675288f2bfd990a5129f13a7f9087b06..9f31c734a1e287197e70a619fa8bc7f6482ebaec 100644 (file)
--- a/mdadm.conf.5
+++ b/mdadm.conf.5
@@ -53,9 +53,20 @@ Also, there may be several device lines present in the file.
 
 Alternatively, a
 .B device
 
 Alternatively, a
 .B device

-line can contain the word
+line can contain either of both of the  words
+.B containers
+and

 .BR partitions .
 .BR partitions .

-This will cause
+The word
+.B containers
+will cause
+.I mdadm
+to look for assembled CONTAINER arrays and included them as a source
+for assembling further arrays.
+
+The word
+.I partitions
+will cause

 .I mdadm
 to read
 .I /proc/partitions
 .I mdadm
 to read
 .I /proc/partitions


@@ -67,7 +78,7 @@ but only the major and minor device numbers.  It scans
 .I /dev
 to find the name that matches the numbers.
 
 .I /dev
 to find the name that matches the numbers.
 

-If no DEVICE line is present, then "DEVICE partitions" is assumed.
+If no DEVICE line is present, then "DEVICE partitions containers" is assumed.

 
 For example:
 .IP
 
 For example:
 .IP


@@ -75,22 +86,35 @@ DEVICE /dev/hda* /dev/hdc*
 .br
 DEV    /dev/sd*
 .br
 .br
 DEV    /dev/sd*
 .br

-DEVICE /dev/discs/disc*/disc
+DEVICE /dev/disk/by-path/pci*

 .br
 DEVICE partitions
 
 .TP
 .B ARRAY
 The ARRAY lines identify actual arrays.  The second word on the line
 .br
 DEVICE partitions
 
 .TP
 .B ARRAY
 The ARRAY lines identify actual arrays.  The second word on the line

-should be the name of the device where the array is normally
+may be the name of the device where the array is normally

 assembled, such as
 assembled, such as

-.BR  /dev/md1 .
+.B /dev/md1
+or
+.BR /dev/md/backup .
+If the name does not start with a slash
+.RB (' / '),
+it is treated as being in
+.BR /dev/md/ .
+Alternately the word
+.B <ignore>
+(complete with angle brackets) can be given in which case any array
+which matches the rest of the line will never be automatically assembled.
+If no device name is given,
+.I mdadm
+will use various heuristics to determine an appropriate name.
+

 Subsequent words identify the array, or identify the array as a member
 of a group. If multiple identities are given,
 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:
 Subsequent words identify the array, or identify the array as a member
 of a group. If multiple identities are given,
 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
 .B uuid=
 .RS 4
 .TP
 .B uuid=


@@ -135,6 +159,7 @@ this is mainly for compatibility with the output of
 .TP
 .B spares=
 The value is a number of spare devices to expect the array to have.
 .TP
 .B spares=
 The value is a number of spare devices to expect the array to have.

+The sole use of this keyword and value is as follows:

 .B mdadm \-\-monitor
 will report an array if it is found to have fewer than this number of
 spares when
 .B mdadm \-\-monitor
 will report an array if it is found to have fewer than this number of
 spares when


@@ -157,10 +182,15 @@ or missing drive but no spare.
 
 .TP
 .B auto=
 
 .TP
 .B auto=

-This option declares to
+This option is rarely needed with mdadm-3.0, particularly if use with
+the Linux kernel v2.6.28 or later.
+It tells

 .I mdadm
 .I 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.
+whether to use partitionable array or non-partitionable arrays and,
+in the absence of
+.IR udev ,
+how many partition devices to create.  From 2.6.28 all md array
+devices are partitionable, hence this option is not needed.

 
 The value of this option can be "yes" or "md" to indicate that a
 traditional, non-partitionable md array should be created, or "mdp",
 
 The value of this option can be "yes" or "md" to indicate that a
 traditional, non-partitionable md array should be created, or "mdp",


@@ -189,6 +219,18 @@ Specify the metadata format that the array has.  This is mainly
 recognised for comparability with the output of
 .BR "mdadm \-Es" .
 
 recognised for comparability with the output of
 .BR "mdadm \-Es" .
 

+.TP
+.B container=
+Specify that this array is a member array of some container.  The
+value given can be either a path name in /dev, or a UUID of the
+container array.
+
+.TP
+.B member=
+Specify that this array is a member array of some container.  Each
+type of container has some way to enumerate member arrays, often a
+simple sequence number.  The value identifies which member of a
+container the array is.  It will usually accompany a "container=" word.

 .RE
 
 .TP
 .RE
 
 .TP


@@ -294,26 +336,181 @@ to suppress this symlink creation.
 The
 .B homehost
 line gives a default value for the
 The
 .B homehost
 line gives a default value for the

-.B --homehost=
-option to mdadm.  There should be exactly one other word on the line.
-It should either exactly
-.B <system>
-or a host name.
+.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
+.BR <system>,
+.B <none>
+and
+.BR <ignore> .

 If
 .B <system>
 is given, then the
 .BR gethostname ( 2 )
 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>
+is given, then a flag is set so that when arrays are being
+auto-assembled the checking of the recorded
+.I homehost
+is disabled.
+If
+.B <ignore>
+is given it is also possible to give an explicit name which will be
+used when creating arrays.  This is the only case when there can be
+more that one other word on the
+.B HOMEHOST
+line.
+
+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
 When arrays are created, this host name will be stored in the

-metadata.  When arrays are assembled using auto-assembly, only arrays
-with this host name stored in the metadata will be considered.
+metadata.  When arrays are assembled using auto-assembly, arrays which
+do not record the correct homehost name in their metadata will be
+assembled using a "foreign" name.  A "foreign" name alway ends with a
+digit string preceded by an underscore to differentiate it
+from any possible local name. e.g.
+.B /dev/md/1_1
+or
+.BR /dev/md/home_0 .
+.TP
+.B AUTO
+A list of names of metadata format can be given, each preceded by a
+plus or minus sign.  Also the word
+.I homehost
+is allowed as is
+.I all
+preceded by plus or minus sign.
+.I all
+is usually last.
+
+When
+.I mdadm
+is auto-assembling an array, either via
+.I \-\-assemble
+or
+.I \-\-incremental
+and it finds metadata of a given type, it checks that metadata type
+against those listed in this line.  The first match wins, where
+.I all
+matches anything.
+If a match is found that was preceded by a plus sign, the auto
+assembly is allowed.  If the match was preceded by a minus sign, the
+auto assembly is disallowed.  If no match is found, the auto assembly
+is allowed.
+
+If the metadata indicates that the array was created for
+.I this
+host, and the word
+.I homehost
+appears before any other match, then the array is treated as a valid
+candidate for auto-assembly.
+
+This can be used to disable all auto-assembly (so that only arrays
+explicitly listed in mdadm.conf or on the command line are assembled),
+or to disable assembly of certain metadata types which might be
+handled by other software.  It can also be used to disable assembly of
+all foreign arrays - normally such arrays are assembled but given a
+non-deterministic name in
+.BR /dev/md/ .
+
+The known metadata types are
+.BR 0.90 ,
+.BR 1.x ,
+.BR ddf ,
+.BR imsm .
+
+.TP
+.B POLICY
+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. 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
+.I domains
+of the new disk or if both arrays have the same
+.IR spare-group .
+
+To update hot plug configuration it is necessary to execute
+.B mdadm \-\-udev\-rules
+command after changing the config file
+
+Key words used in the
+.I POLICY
+line and supported values are:
+
+.RS 7
+.TP
+.B domain=
+any arbitrary string
+.TP
+.B metadata=
+0.9 1.x ddf or imsm
+.TP
+.B path=
+file glob matching anything from
+.B /dev/disk/by-path
+.B type=
+either 
+.B disk
+or
+.BR part .
+.TP
+.B action=
+include, re-add, spare, spare-same-slot, or force-spare
+
+.P
+The
+.I action
+item determines the automatic behavior allowed for devices matching the
+.I path
+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.
+.TP
+.B include
+allows adding a disk to an array if metadata on that disk matches that array
+.TP
+.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
+.TP
+.B spare
+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
+as above and the disk will become a spare in remaining cases
+.RE

 
 .SH EXAMPLE
 DEVICE /dev/sd[bcdjkl]1
 .br
 DEVICE /dev/hda1 /dev/hdb1
 
 
 .SH EXAMPLE
 DEVICE /dev/sd[bcdjkl]1
 .br
 DEVICE /dev/hda1 /dev/hdb1
 

-# /dev/md0 is known by its UID.
+# /dev/md0 is known by its UUID.

 .br
 ARRAY /dev/md0 UUID=3aaa0122:29827cfa:5331ad66:ca767371
 .br
 .br
 ARRAY /dev/md0 UUID=3aaa0122:29827cfa:5331ad66:ca767371
 .br


@@ -346,7 +543,25 @@ ARRAY /dev/md5 uuid=19464854:03f71b1b:e0df2edd:246cc977
 ARRAY /dev/md/home UUID=9187a482:5dde19d9:eea3cc4a:d646ab8b
 .br
            auto=part
 ARRAY /dev/md/home UUID=9187a482:5dde19d9:eea3cc4a:d646ab8b
 .br
            auto=part

-
+.br
+POLICY domain=domain1 metadata=imsm path=pci-0000:00:1f.2-scsi-*
+.br
+           action=spare
+.br
+POLICY domain=domain1 metadata=imsm path=pci-0000:04:00.0-scsi-[01]*
+.br
+           action=include
+.br
+# One domain comprising of devices attached to specified paths is defined.
+.br
+# Bare device matching first path will be made an imsm spare on hot plug.
+.br
+# If more than one array is created on devices belonging to domain1 and
+.br
+# one of them becomes degraded, then any imsm spare matching any path for
+.br
+# given domain name can be migrated.
+.br

 MAILADDR root@mydomain.tld
 .br
 PROGRAM /usr/sbin/handle\-mdadm\-events
 MAILADDR root@mydomain.tld
 .br
 PROGRAM /usr/sbin/handle\-mdadm\-events


@@ -354,6 +569,8 @@ PROGRAM /usr/sbin/handle\-mdadm\-events
 CREATE group=system mode=0640 auto=part\-8
 .br
 HOMEHOST <system>
 CREATE group=system mode=0640 auto=part\-8
 .br
 HOMEHOST <system>

+.br
+AUTO +1.x homehost -all

 
 .SH SEE ALSO
 .BR mdadm (8),
 
 .SH SEE ALSO
 .BR mdadm (8),