Vantec NST-400MX-SR User Guide - Page 19

RAID 1： It allows the device automatically to copy data to both hard drives. It stores all data in duplicate on separate drives to protect against data loss due to drive failure. It provides the highest level of data protection for critical data that you cannot afford to lose if a hard drive fails. The capacity is equal to the smaller of the two hard drives. If one drive fails, the SAFE volume is still usable, but it is in a vulnerable state because its mirrored hard drive is inaccessible. When the offline drive comes back online, the appliance begins a rebuild process immediately to restore data redundancy. Although the volume remains available during the rebuild process, the volume is susceptible to data loss through damage to the remaining drive until redundancy is restored at the end of the rebuild and verification process. Host access takes precedence over the rebuild process. If you continue to use the SAFE volume during the rebuild, the rebuild process will take a longer time to complete, and the host data transfer performance will also be affected. Raid 1 250GB NST-400MX-SR Port 0 Port 1 Drive A 250GB Drive B 250GB Equal hard drives Raid 1 250GB NST-400MX-SR Port 0 Port 1 Drive A 250GB Drive A 750GB Unequal hard drives RAID Mode Selection 18