Package mdadm

The mdadm program controls Linux md devices (software RAID arrays)

http://www.kernel.org/pub/linux/utils/raid/mdadm/

The mdadm program is used to create, manage, and monitor Linux MD (software
RAID) devices. As such, it provides similar functionality to the raidtools
package. However, mdadm is a single program, and it can perform
almost all functions without a configuration file, though a configuration
file can be used to help with some common tasks.

Special Files
Special File Description
md Multiple Device driver aka Linux Software RAID
File Formats
File Description
mdadm.conf configuration for management of Software RAID with mdadm
System Administration
Command Description
mdadm manage MD devices aka Linux Software RAID
mdmon monitor MD external metadata arrays