========================= mdadm
mdadm --help-options
Any parameter that does not start with '-' is treated as a device name
The first such name is often the name of an md device.  Subsequent
names are often names of component devices.
Some common options are:
  --help        -h   : General help message or, after above option,
                       mode specific help message
  --help-options     : This help message
  --version     -V   : Print version information for mdadm
  --verbose     -v   : Be more verbose about what is happening
  --brief       -b   : Be less verbose, more brief
  --force       -f   : Override normal checks and be more forceful

  --assemble    -A   : Assemble an array
  --build       -B   : Build a legacy array
  --create      -C   : Create a new array
  --detail      -D   : Display details of an array
  --examine     -E   : Examine superblock on an array component
  --monitor     -F   : monitor (follow) some arrays
  --query       -Q   : Display general information about how a
                       device relates to the md driver
-------------------------
mdadm [mode] <raiddevice> [options] <component disks>

mdadm --create --verbose /dev/md0 --level=0 
        --raid-devices=2  /dev/sdb1 /dev/sdc1

mdadm -Cv /dev/md0 -l5 -n5 -c128 /dev/sd{a,b,c,d,e}1
mdadm -S /dev/md0   stop array

mdadm --detail --scan
you may output the above command into mdadm.conf file which might look like
this:

DEVICE		/dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1
ARRAY		/dev/md0 devices=/dev/sda1,/dev/sdb1
ARRAY		/dev/md1 devices=/dev/sdc1,/dev/sdd1
mdadm -As /dev/md0	start an array

-A option denotes assemble mode. You can also use --assemble. The -s or --scan option tells mdadm to look in /etc/mdadm.conf for information about arrays and devices. If you want to start every array listed in /etc/mdadm.conf, don't specify an md device on the command line.

mdadm -A /dev/md0 /dev/sdb1 /dev/sdc1	manual asembly of and array

mdadm -E /dev/sdc1	examine an array


========================= mdadm
http://www.tldp.org/HOWTO/Software-RAID-HOWTO-7.html#ss7.3
    * mdadm can diagnose, monitor and gather detailed information about your arrays
    * mdadm is a single centralized program and not a collection of disperse programs, so there's a common syntax for every RAID management command
    * mdadm can perform almost all of its functions without having a configuration file and does not use one by default
    * Also, if a configuration file is needed, mdadm will help with management of it's contents
-----------------
mdadm --create --help

       Usage: mdadm --assemble md-device options-and-component-devices...

       Usage: mdadm --assemble --scan md-devices-and-options...

       Usage: mdadm --assemble --scan options...

Usage:   mdadm  --build  device  --chunk=X  --level=Y  --raid-devices=Z
                   devices
         mdadm /dev/md0 -f /dev/hda1 -r /dev/hda1 -a /dev/hda1
       will  firstly mark /dev/hda1 as faulty in /dev/md0 and will then remove
       it from the array and finally add it back in as a spare.  However  only
       one md array can be affected by a single command.

         mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/hd[ac]1
       Create /dev/md0 as a RAID1 array consisting of /dev/hda1 and /dev/hdc1.

         echo 'DEVICE /dev/hd*[0-9] /dev/sd*[0-9]' > mdadm.conf
         mdadm --detail --scan >> mdadm.conf

         echo 'DEVICE /dev/hd[a-z] /dev/sd*[a-z]' > mdadm.conf
         mdadm --examine --scan --config=mdadm.conf >>  mdadm.conf  This  will
       find  what  arrays  could be assembled from existign IDE and SCSI whole
       drives (not partitions) and store the information is the  format  of  a
       config file.  This file is very likely to contain unwanted detail, par-
       ticularly the devices= entries.   It  should  be  reviewed  and  edited
       before being used as an actual config file.