.\" 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 8 "" v3.0-devel1
+.TH MDADM 8 "" v3.0-devel3
.SH NAME
mdadm \- manage MD devices
.I aka
is not a Software RAID mechanism, but does involve
multiple devices:
each device is a path to one common physical storage device.
+New installations should not use md/multipath as it is not well
+supported and has no ongoing development. Use the Device Mapper based
+multipath-tools instead.
.B FAULTY
is also not true RAID, and it only involves one device. It
provides a layer over a true device that can be used to inject faults.
-B CONTAINER
+.B CONTAINER
is different again. A
.B CONTAINER
is a collection of devices that are
managed as a set. This is similar to the set of devices connected to
a hardware RAID controller. The set of devices may contain a number
-of different RAID arrays each utilising some (or all) blocks from a
+of different RAID arrays each utilising some (or all) of the blocks from a
number of the devices in the set. For example, two devices in a 5-device set
-might form a RAID1 used the whole devices. The remaining three might
+might form a RAID1 using the whole devices. The remaining three might
have a RAID5 over the first half of each device, and a RAID0 over the
second half.
.I mdadm
creates a
.B CONTAINER
-device, it just represents the metadata. Other normal arrays (RAID1
-etc) can be created inside that container.
-
-
-.\".I mdadm
-.\"is a program that can be used to create, manage, and monitor
-.\"MD devices. As
-.\"such it provides a similar set of functionality to the
-.\".B raidtools
-.\"packages.
-.\"The key differences between
-.\".I mdadm
-.\"and
-.\".B raidtools
-.\"are:
-.\".IP \(bu 4
-.\".I mdadm
-.\"is a single program and not a collection of programs.
-.\".IP \(bu 4
-.\".I mdadm
-.\"can perform (almost) all of its functions without having a
-.\"configuration file and does not use one by default. Also
-.\".I mdadm
-.\"helps with management of the configuration
-.\"file.
-.\".IP \(bu 4
-.\".I mdadm
-.\"can provide information about your arrays (through Query, Detail, and Examine)
-.\"that
-.\".B raidtools
-.\"cannot.
-.\".P
-.\".I mdadm
-.\"does not use
-.\".IR /etc/raidtab ,
-.\"the
-.\".B raidtools
-.\"configuration file, at all. It has a different configuration file
-.\"with a different format and a different purpose.
+device, the device just represents the metadata. Other normal arrays (RAID1
+etc) can be created inside the container.
.SH MODES
mdadm has several major modes of operation:
system. As each device is detected,
.I mdadm
has a chance to include it in some array as appropriate.
-.P
+
If a
.B CONTAINER
is passed to
.B CONTAINER
will be created, and normal arrays can be created in that container.
.IP imsm
-Use the Intel Matrix Storage Manager metadata format. This creates a
+Use the Intel(R) Matrix Storage Manager metadata format. This creates a
.B CONTAINER
-which is managed in a similar manner to DDF.
+which is managed in a similar manner to DDF, and is supported by an
+option-rom on some platforms:
+.IP
+.B http://www.intel.com/design/chipsets/matrixstorage_sb.htm
+.PP
.RE
.TP
for the given homehost will be reported as such.
When using Auto-Assemble, only arrays tagged for the given homehost
-will be assembled.
+will be allowed to use 'local' names (i.e. not ending in '_' followed
+by a digit string).
.SH For create, build, or grow:
will not try to be so clever.
.TP
-.BR \-a ", " "\-\-auto{=no,yes,md,mdp,part,p}{NN}"
-Instruct mdadm to create the device file if needed, possibly allocating
+.BR \-a ", " "\-\-auto{=yes,md,mdp,part,p}{NN}"
+Instruct mdadm how to create the device file if needed, possibly allocating
an unused minor number. "md" causes a non-partitionable array
-to be used. "mdp", "part" or "p" causes a partitionable array (2.6 and
+to be used (though since Linux 2.6.28, these array devices are in fact
+partitionable). "mdp", "part" or "p" causes a partitionable array (2.6 and
later) to be used. "yes" requires the named md device to have
a 'standard' format, and the type and minor number will be determined
-from this. See DEVICE NAMES below.
+from this. With mdadm 3.0, device creation is normally left up to
+.I udev
+so this option is unlikely to be needed.
+See DEVICE NAMES below.
The argument can also come immediately after
"\-a". e.g. "\-ap".
.BR \-D ", " \-\-detail
Print detail of one or more md devices.
+.TP
+.BR \-\-detail\-platform
+Print detail of the platform's raid capabilities (firmware / hardware
+topology) for a given metadata format.
+
.TP
.BR \-Y ", " \-\-export
When used with
.TP
.BR \-\-wait\-clean
-For each md device given, arrange for the array to be marked clean as
-soon as possible. Also, quiesce resync so that the monitor for external
-metadata arrays (mdmon) has an opportunity to checkpoint the resync
-position.
+For each md device given, or each device in /proc/mdstat if
+.B \-\-scan
+is given, arrange for the array to be marked clean as soon as possible.
+Also, quiesce resync so that the monitor for external metadata arrays
+(mdmon) has an opportunity to checkpoint the resync position.
.I mdadm
will return with success if the array uses external metadata and we
successfully waited. For native arrays this returns immediately as the
Run any array assembled as soon as a minimal number of devices are
available, rather than waiting until all expected devices are present.
+.TP
+.B \-\-no\-degraded
+This allows the hot-plug system to prevent arrays from running when it knows
+that more disks may arrive later in the discovery process.
+
.TP
.BR \-\-scan ", " \-s
Only meaningful with
There was an error while trying to get information about the device.
.RE
+.TP
+.B \-\-detail\-platform
+Print detail of the platform's raid capabilities (firmware / hardware
+topology). If the metadata is specified with
+.B \-e
+or
+.B \-\-metadata=
+then the return status will be:
+.RS
+.TP
+0
+metadata successfully enumerated its platform components on this system
+.TP
+1
+metadata is platform independent
+.TP
+2
+metadata failed to find its platform components on this system
+.RE
+
.TP
.B \-\-examine
The device should be a component of an md array.
projects / thirdparty / mdadm.git / blobdiff