18.6. Configuring RAID Sets
Most RAID sets are configured during creation, typically through the firmware menu or from the installer. In some cases, you may need to create or modify RAID sets after installing the system, preferably without having to reboot the machine and enter the firmware menu to do so.
Some hardware RAID controllers allow you to configure RAID sets on-the-fly or even define completely new sets after adding extra disks. This requires the use of driver-specific utilities, as there is no standard API for this. For more information, see your hardware RAID controller's driver documentation for information on this.
mdadm command-line tool is used to manage software RAID in Linux, i.e.
mdraid. For information on the different
mdadm modes and options, see
man mdadm. The
man page also contains useful examples for common operations like creating, monitoring, and assembling software RAID arrays.
As the name suggests,
dmraid is used to manage device-mapper RAID sets. The
dmraid tool finds ATARAID devices using multiple metadata format handlers, each supporting various formats. For a complete list of supported formats, run
As mentioned earlier in Section 18.3, “Linux RAID Subsystems”, the
dmraid tool cannot configure RAID sets after creation. For more information about using