# Create a RIAD5 MD device with five members
$ mdadm --create /dev/md2 --level=5 --raid-devices=6 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1 /dev/sdg1 /dev/sdh1

# Stop an md device so we can reuse the devices
$ mdadm -S /dev/md2

# Print the available md devices
$ mdadm --detail --scan
ARRAY /dev/md0 level=raid1 num-devices=2 UUID=039a7497:72bfae8f:6ab0b026:3b063457
ARRAY /dev/md1 level=raid1 num-devices=2 UUID=98c089ae:a88d40a7:c22d9771:da50dfe5
ARRAY /dev/md2 level=raid5 num-devices=6 spares=1 UUID=017379a7:72298d9d:5e1ae2a2:2eb50769

# Populate /etc/mdadm.conf with the devices we found during the scan
$ mdadm --detail --scan > /etc/mdadm.conf 

# Query the details of an MD device
/sbin/mdadm --query /dev/md2
/dev/md2: 1164.41GiB raid5 6 devices, 0 spares. Use mdadm --detail for more detail.

# Get detailed information on a MD device
$ /sbin/mdadm --detail /dev/md2
/dev/md2:
        Version : 00.90.03
  Creation Time : Mon Mar  5 22:02:08 2007
     Raid Level : raid5
     Array Size : 976751616 (931.50 GiB 1000.19 GB)
    Device Size : 244187904 (232.88 GiB 250.05 GB)
   Raid Devices : 5
  Total Devices : 5
Preferred Minor : 2
    Persistence : Superblock is persistent

    Update Time : Mon Mar  5 22:02:24 2007
          State : active, degraded, recovering
 Active Devices : 4
Working Devices : 5
 Failed Devices : 0
  Spare Devices : 1

         Layout : left-symmetric
     Chunk Size : 64K

 Rebuild Status : 0% complete

           UUID : b98af6a8:21b57b11:77f6c603:283ae710
         Events : 0.3

    Number   Major   Minor   RaidDevice State
       0       8       33        0      active sync   /dev/sdc1
       1       8       49        1      active sync   /dev/sdd1
       2       8       65        2      active sync   /dev/sde1
       3       8       81        3      active sync   /dev/sdf1
       5       8       97        4      spare rebuilding   /dev/sdg1

# Monitor the progress of an MD device rebuild
$ while :; do clear; mdadm --detail /dev/md2; sleep 10 ; done

# Start MD device md2 which has two devices associated with it
$ mdadm -A /dev/md0 /dev/sdb1 /dev/sdc1

# Remove a device from the meta device MD2
$ mdadm /dev/md0 --fail /dev/sdc1 --remove /dev/sdc1

# Monitor the md device MD2 every 60 seconds
$ mdadm --monitor --mail=sysadmin --delay=60 /dev/md2

# Add a block changed bitmap to the MD device
$ /sbin/mdadm /dev/md0 -Gb internal

# Add a hot spare to the meta device md2
$ /sbin/mdadm --add /dev/md2 /dev/sdh1