.I mdadm
will be silent unless there is something really important to report.
-.TP
-.BR \-\-offroot
-Set first character of argv[0] to @ to indicate mdadm was launched
-from initrd/initramfs and should not be shutdown by systemd as part of
-the regular shutdown process. This option is normally only used by
-the system's initscripts. Please see here for more details on how
-systemd handled argv[0]:
-.IP
-.B http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons
-.PP
-
.TP
.BR \-f ", " \-\-force
Note: external bitmaps are only known to work on ext2 and ext3.
Storing bitmap files on other filesystems may result in serious problems.
+When creating an array on devices which are 100G or larger,
+.I mdadm
+automatically adds an internal bitmap as it will usually be
+beneficial. This can be suppressed with
+.B "\-\-bitmap=none".
+
.TP
.BR \-\-bitmap\-chunk=
Set the chunksize of the bitmap. Each bit corresponds to that many
.BR no\-bitmap ,
.BR bbl ,
.BR no-\bbl ,
+.BR metadata ,
or
.BR super\-minor .
to determine the maximum usable amount of space on each device and
update the relevant field in the metadata.
+The
+.B metadata
+option only works on v0.90 metadata arrays and will convert them to
+v1.0 metadata. The array must not be dirty (i.e. it must not need a
+sync) and it must not have a write-intent bitmap.
+
+The old metadata will remain on the devices, but will appear older
+than the new metadata and so will usually be ignored. The old metadata
+(or indeed the new metadata) can be removed by giving the appropriate
+.B \-\-metadata=
+option to
+.BR \-\-zero\-superblock .
+
The
.B no\-bitmap
option can be used when an array has an internal bitmap which is
.TP
.BR \-r ", " \-\-remove
remove listed devices. They must not be active. i.e. they should
-be failed or spare devices. As well as the name of a device file
+be failed or spare devices.
+
+As well as the name of a device file
(e.g.
.BR /dev/sda1 )
the words
-.B failed
-and
+.BR failed ,
.B detached
+and names like
+.B set-A
can be given to
.BR \-\-remove .
The first causes all failed device to be removed. The second causes
any device which is no longer connected to the system (i.e an 'open'
returns
.BR ENXIO )
-to be removed. This will only succeed for devices that are spares or
-have already been marked as failed.
+to be removed.
+The third will remove a set as describe below under
+.BR \-\-fail .
.TP
.BR \-f ", " \-\-fail
Mark listed devices as faulty.
As well as the name of a device file, the word
.B detached
-can be given. This will cause any device that has been detached from
+or a set name like
+.B set\-A
+can be given. The former will cause any device that has been detached from
the system to be marked as failed. It can then be removed.
+For RAID10 arrays where the number of copies evenly divides the number
+of devices, the devices can be conceptually divided into sets where
+each set contains a single complete copy of the data on the array.
+Sometimes a RAID10 array will be configured so that these sets are on
+separate controllers. In this case all the devices in one set can be
+failed by giving a name like
+.B set\-A
+or
+.B set\-B
+to
+.BR \-\-fail .
+The appropriate set names are reported by
+.BR \-\-detail .
+
.TP
.BR \-\-set\-faulty
same as
.B 1.x
metadata supports bad-blocks lists.
+.TP
+.BI \-\-dump= directory
+.TP
+.BI \-\-restore= directory
+Save metadata from lists devices, or restore metadata to listed devices.
+
.TP
.BR \-R ", " \-\-run
start a partially assembled array. If
If the device is a container and the argument to \-\-kill\-subarray
specifies an inactive subarray in the container, then the subarray is
deleted. Deleting all subarrays will leave an 'empty-container' or
-spare superblock on the drives. See \-\-zero\-superblock for completely
+spare superblock on the drives. See
+.B \-\-zero\-superblock
+for completely
removing a superblock. Note that some formats depend on the subarray
index for generating a UUID, this command will fail if it would change
the UUID of an active subarray.
.\".B \-\-size
.\"is given, the apparent size of the smallest drive given is used.
+If the array type supports a write-intent bitmap, and if the devices
+in the array exceed 100G is size, an internal write-intent bitmap
+will automatically be added unless some other option is explicitly
+requested with the
+.B \-\-bitmap
+option. In any case space for a bitmap will be reserved so that one
+can be added layer with
+.BR "\-\-grow \-\-bitmap=internal" .
+
If the metadata type supports it (currently only 1.x metadata), space
will be allocated to store a bad block list. This allows a modest
number of bad blocks to be recorded, allowing the drive to remain in
without listing any devices will cause all devices listed in the
config file to be examined.
+.TP
+.BI \-\-dump= directory
+If the device contains RAID metadata, a file will be created in the
+.I directory
+and the metadata will be written to it. The file will be the same
+size as the device and have the metadata written in the file at the
+same locate that it exists in the device. However the file will be "sparse" so
+that only those blocks containing metadata will be allocated. The
+total space used will be small.
+
+The file name used in the
+.I directory
+will be the base name of the device. Further if any links appear in
+.I /dev/disk/by-id
+which point to the device, then hard links to the file will be created
+in
+.I directory
+based on these
+.I by-id
+names.
+
+Multiple devices can be listed and their metadata will all be stored
+in the one directory.
+
+.TP
+.BI \-\-restore= directory
+This is the reverse of
+.BR \-\-dump .
+.I mdadm
+will locate a file in the directory that has a name appropriate for
+the given device and will restore metadata from it. Names that match
+.I /dev/disk/by-id
+names are preferred, however if two of those refer to different files,
+.I mdadm
+will not choose between them but will abort the operation.
+
+If a file name is given instead of a
+.I directory
+then
+.I mdadm
+will restore from that file to a single device, always provided the
+size of the file matches that of the device, and the file contains
+valid metadata.
.TP
.B \-\-stop
The devices should be active md arrays which will be deactivated, as
.I mdadm
will create and devices that are needed.
+.TP
+.B IMSM_NO_PLATFORM
+A key value of IMSM metadata is that it allows interoperability with
+boot ROMs on Intel platforms, and with other major operating systems.
+Consequently,
+.I mdadm
+will only allow an IMSM array to be created or modified if detects
+that it is running on an Intel platform which supports IMSM, and
+supports the particular configuration of IMSM that is being requested
+(some functionality requires newer OROM support).
+
+These checks can be suppressed by setting IMSM_NO_PLATFORM=1 in the
+environment. This can be useful for testing or for disaster
+recovery. You should be aware that interoperability may be
+compromised by setting this value.
.SH EXAMPLES
.B " mdadm \-\-query /dev/name-of-device"
The standard names for non-partitioned arrays (the only sort of md
array available in 2.4 and earlier) are of the form
.IP
-/dev/mdNN
+.RB /dev/md NN
.PP
where NN is a number.
The standard names for partitionable arrays (as available from 2.6
-onwards) are of the form
+onwards) are of the form:
.IP
-/dev/md_dNN
+.RB /dev/md_d NN
+.PP
+Partition numbers should be indicated by adding "pMM" to these, thus "/dev/md/d1p2".
.PP
-Partition numbers should be indicated by added "pMM" to these, thus "/dev/md/d1p2".
+From kernel version 2.6.28 the "non-partitioned array" can actually
+be partitioned. So the "md_d\fBNN\fP"
+names are no longer needed, and
+partitions such as "/dev/md\fBNN\fPp\fBXX\fp"
+are possible.
.PP
-From kernel version, 2.6.28 the "non-partitioned array" can actually
-be partitioned. So the "md_dNN" names are no longer needed, and
-partitions such as "/dev/mdNNpXX" are possible.
+From kernel version 2.6.29 standard names can be non-numeric following
+the form:
+.IP
+.RB /dev/md_ XXX
+.PP
+where
+.B XXX
+is any string. These names are supported by
+.I mdadm
+since version 3.3 provided they are enabled in
+.IR mdadm.conf .
.SH NOTE
.I mdadm
was previously known as
.IR mdctl .
-.P
-.I mdadm
-is completely separate from the
-.I raidtools
-package, and does not use the
-.I /etc/raidtab
-configuration file at all.
.SH SEE ALSO
For further information on mdadm usage, MD and the various levels of
.B http://raid.wiki.kernel.org/
.PP
(based upon Jakob \(/Ostergaard's Software\-RAID.HOWTO)
-.\".PP
-.\"for new releases of the RAID driver check out:
-.\"
-.\".IP
-.\".UR ftp://ftp.kernel.org/pub/linux/kernel/people/mingo/raid-patches
-.\"ftp://ftp.kernel.org/pub/linux/kernel/people/mingo/raid-patches
-.\".UE
-.\".PP
-.\"or
-.\".IP
-.\".UR http://www.cse.unsw.edu.au/~neilb/patches/linux-stable/
-.\"http://www.cse.unsw.edu.au/~neilb/patches/linux-stable/
-.\".UE
.PP
The latest version of
.I mdadm
.IR mdmon (8),
.IR mdadm.conf (5),
.IR md (4).
-.PP
-.IR raidtab (5),
-.IR raid0run (8),
-.IR raidstop (8),
-.IR mkraid (8).
projects / thirdparty / mdadm.git / blobdiff