RAID Management

OpenRG supports Redundant Array of Independent Disks (RAID) on storage devices connected to the gateway internally, by USB or by FireWire. A RAID device is a logical device that has physical devices underlying it. These physical devices are disk partitions.

The supported RAID levels are:

• Level 0 - Provides data striping, or spreading out blocks of each file across multiple disk drives, but no redundancy. This improves performance but does not deliver fault tolerance. If one drive fails then all data in the array is lost.

• Level 1 - Provides disk mirroring. This is a technique in which data is written to two duplicate disks simultaneously, providing data redundancy. This method improves performance and delivers fault tolerance.

• Level 5 - With a minimum of three disks, this level provides data striping and utilizes one disk for backup information, which enables it to restore any other disk in the array.

Before creating the RAID device, you must create disk partitions (see section 6.4.1.1) on the different disk drives. Each RAID device can have multiple underlying devices (partitions). When using RAID1, it is recommended that these partitions be of the same size, to avoid disk-space loss due to mirroring.

A disk partition configured with RAID can no longer be managed as a regular partition, but only be controlled by the RAID device. From the moment RAID is configured, it is the RAID device that can be shared, scanned, formatted and mounted as a regular partition.