Biostar TFORCE4 U TForce4 U user's manual - Page 14

Biostar T-Series 3.3 HOW RAID WORKS RAID 0: The controller "stripes" data across multiple drives in a RAID 0 array system. It breaks up a large file into smaller blocks and performs disk reads and writes across multiple drives in parallel. The size of each block is determined by the stripe size parameter, which you set during the creation of the RAID set based on the system environment. This technique reduces overall disk access time and offers high bandwidth. Features and Benefits ­ Drives: Minimum 1, and maximum is up to 6 or 8. Depending on the platform. ­ Uses: Intended for non-critical data requiring high data throughput, or any environment that does not require fault tolerance. ­ Benefits: provides increased data throughput, especially for large files. No capacity loss penalty for parity. ­ Drawbacks: Does not deliver any fault tolerance. If any drive in the array fails, all data is lost. ­ Fault Tolerance: No. TForce4/ TForce4 U RAID 1: Every read and write is actually carried out in parallel across 2 disk drives in a RAID 1 array system. The mirrored (backup) copy of the data can reside on the same disk or on a second redundant drive in the array. RAID 1 provides a hot-standby copy of data if the active volume or drive is corrupted or becomes unavailable because of a hardware failure. RAID techniques can be applied for high-availability solutions, or as a form of automatic backup that eliminates tedious manual backups to more expensive and less reliable media. Features and Benefits ­ Drives: Minimum 2, and maximum is 2. ­ Uses: RAID 1 is ideal for small databases or any other application that requires fault tolerance and minimal capacity. ­ Benefits: Provides 100% data redundancy. Should one drive fail, the controller switches to the other drive. ­ Drawbacks: Requires 2 drives for the storage space of one drive. Performance is impaired during drive rebuilds. ­ Fault Tolerance: Yes. Block 1 Block 3 Block 5 Block 2 Block 4 Block 6 Block 1 Block 2 Block 3 Block 1 Block 2 Block 3 12 User's Manual