mdadm --version (return code: 0)
mdadm - v3.3 - 3rd September 2013
mdadm --help (return code: 0)
mdadm is used for building, managing, and monitoring
Linux md devices (aka RAID arrays)
Usage: mdadm --create device options...
Create a new array from unused devices.
mdadm --assemble device options...
Assemble a previously created array.
mdadm --build device options...
Create or assemble an array without metadata.
mdadm --manage device options...
make changes to an existing array.
mdadm --misc options... devices
report on or modify various md related devices.
mdadm --grow options device
resize/reshape an active array
mdadm --incremental device
add/remove a device to/from an array as appropriate
mdadm --monitor options...
Monitor one or more array for significant changes.
mdadm device options...
Shorthand for --manage.
Any parameter that does not start with '-' is treated as a device name
or, for --examine-bitmap, a file name.
The first such name is often the name of an md device. Subsequent
names are often names of component devices.
For detailed help on the above major modes use --help after the mode
e.g.
mdadm --assemble --help
For general help on options use
mdadm --help-options