Asus PCI-DA2100 User Manual - Page 295

ASUS GUI RAID Manager: Array Management 4.1 Background Information Redundant Arrays of Independent Disks (RAID) is a storage technology used to improve the processing capability of storage systems. This technology is designed to provide reliability in disk array systems and to take advantage of the performance gains multiple disks can offer. RAID comes with a redundancy feature that ensures faulttolerant, uninterrupted disk storage operations. In the event of a disk failure, disk access will still continue normally with the failure transparent to the host system. RAID has six levels: RAID 0 ~ 5. RAID levels 1, 3 and 5 are the most commonly used levels, while RAID levels 2 and 4 are the less popular ones. Appendix C, RAID Levels, gives information about these levels, including the benefits of each. ASUS disk array controllers support hot-swapping where a failed drive can be replaced while the disk array system continues to function. Spares can also be assigned so that, as soon as a drive fails, the spare will be automatically configured into the array and reconstruction will commence. 4.1.1 Definition of Terms This section describes some of the disk array terms used in this documentation. ♦ Physical drives. These are the actual SCSI drives installed on the connectors of the SCSI cables. These drives are displayed on the Physical Drives window. ♦ Spare drives. These are physical drives that serve as backups. When a drive fails, the spare is automatically configured into the array, and data reconstruction will 4.1 Background Information 4-3