управлять MD-устройствами, также известными как Linux Software RAID  (manage MD devices aka Linux Software RAID)
  
Options that are not mode-specific are:
-h, --help
              Display general help message or, after one of the above
              options, a mode-specific help message.
       --help-options
              Display more detailed help about command line parsing and
              some commonly used options.
       -V, --version
              Print version information for mdadm.
       -v, --verbose
              Be more verbose about what is happening.  This can be used
              twice to be extra-verbose.  The extra verbosity currently
              only affects --detail --scan and --examine --scan.
       -q, --quiet
              Avoid printing purely informative messages.  With this,
              mdadm will be silent unless there is something really
              important to report.
       -f, --force
              Be more forceful about certain operations.  See the
              various modes for the exact meaning of this option in
              different contexts.
       -c, --config=
              Specify the config file or directory.  Default is to use
              /etc/mdadm.conf and /etc/mdadm.conf.d, or if those are
              missing then /etc/mdadm/mdadm.conf and
              /etc/mdadm/mdadm.conf.d.  If the config file given is
              partitions then nothing will be read, but mdadm will act
              as though the config file contained exactly
                  DEVICE partitions containers
              and will read /proc/partitions to find a list of devices
              to scan, and /proc/mdstat to find a list of containers to
              examine.  If the word none is given for the config file,
              then mdadm will act as though the config file were empty.
              If the name given is of a directory, then mdadm will
              collect all the files contained in the directory with a
              name ending in .conf, sort them lexically, and process all
              of those files as config files.
       -s, --scan
              Scan config file or /proc/mdstat for missing information.
              In general, this option gives mdadm permission to get any
              missing information (like component devices, array
              devices, array identities, and alert destination) from the
              configuration file (see previous option); one exception is
              MISC mode when using --detail or --stop, in which case
              --scan says to get a list of array devices from
              /proc/mdstat.
       -e, --metadata=
              Declare the style of RAID metadata (superblock) to be
              used.  The default is 1.2 for --create, and to guess for
              other operations.  The default can be overridden by
              setting the metadata value for the CREATE keyword in
              mdadm.conf.
              Options are:
              0, 0.90
                     Use the original 0.90 format superblock.  This
                     format limits arrays to 28 component devices and
                     limits component devices of levels 1 and greater to
                     2 terabytes.  It is also possible for there to be
                     confusion about whether the superblock applies to a
                     whole device or just the last partition, if that
                     partition starts on a 64K boundary.
              1, 1.0, 1.1, 1.2 default
                     Use the new version-1 format superblock.  This has
                     fewer restrictions.  It can easily be moved between
                     hosts with different endian-ness, and a recovery
                     operation can be checkpointed and restarted.  The
                     different sub-versions store the superblock at
                     different locations on the device, either at the
                     end (for 1.0), at the start (for 1.1) or 4K from
                     the start (for 1.2).  "1" is equivalent to "1.2"
                     (the commonly preferred 1.x format).  "default" is
                     equivalent to "1.2".
              ddf    Use the "Industry Standard" DDF (Disk Data Format)
                     format defined by SNIA.  When creating a DDF array
                     a CONTAINER will be created, and normal arrays can
                     be created in that container.
              imsm   Use the Intel(R) Matrix Storage Manager metadata
                     format.  This creates a CONTAINER which is managed
                     in a similar manner to DDF, and is supported by an
                     option-rom on some platforms:
                     https://www.intel.com/content/www/us/en/support/products/122484/memory-and-storage/ssd-software/intel-virtual-raid-on-cpu-intel-vroc.html 
       --homehost=
              This will override any HOMEHOST setting in the config file
              and provides the identity of the host which should be
              considered the home for any arrays.
              When creating an array, the homehost will be recorded in
              the metadata.  For version-1 superblocks, it will be
              prefixed to the array name.  For version-0.90 superblocks,
              part of the SHA1 hash of the hostname will be stored in
              the later half of the UUID.
              When reporting information about an array, any array which
              is tagged for the given homehost will be reported as such.
              When using Auto-Assemble, only arrays tagged for the given
              homehost will be allowed to use 'local' names (i.e. not
              ending in '_' followed by a digit string).  See below
              under Auto Assembly.
              The special name "any" can be used as a wild card.  If an
              array is created with --homehost=any then the name "any"
              will be stored in the array and it can be assembled in the
              same way on any host.  If an array is assembled with this
              option, then the homehost recorded on the array will be
              ignored.
       --prefer=
              When mdadm needs to print the name for a device it
              normally finds the name in /dev which refers to the device
              and is shortest.  When a path component is given with
              --prefer mdadm will prefer a longer name if it contains
              that component.  For example --prefer=by-uuid will prefer
              a name in a subdirectory of /dev called by-uuid.
              This functionality is currently only provided by --detail
              and --monitor.
       --home-cluster=
              specifies the cluster name for the md device. The md
              device can be assembled only on the cluster which matches
              the name specified. If this option is not provided, mdadm
              tries to detect the cluster name automatically.