18.4. RAID Support in the Anaconda Installer

The Anaconda installer automatically detects any hardware and firmware RAID sets on a system, making them available for installation. Anaconda also supports software RAID using mdraid, and can recognize existing mdraid sets.
Anaconda provides utilities for creating RAID sets during installation; however, these utilities only allow partitions (as opposed to entire disks) to be members of new sets. To use an entire disk for a set, create a partition on it spanning the entire disk, and use that partition as the RAID set member.
When the root file system uses a RAID set, Anaconda adds special kernel command-line options to the bootloader configuration telling the initrd which RAID set(s) to activate before searching for the root file system.
For instructions on configuring RAID during installation, see the Red Hat Enterprise Linux 7 Installation Guide.