Vantec NST-640S3R-BK User Guide - Page 16

RAID 10 (1) Mode (Mirror): RAID 1(with 2 Drives): This mode allows the device to automatically copy data to 2 sets of 2 hard drives. It stores all data in duplicate to protect against data loss due to drive failure. RAID 10(with 4 Drives): This mode allows the device to automatically copy data to 2 sets of 2 hard drives running RAID 0. It stores all data in duplicate on the two sets of RAID 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 two times the smallest drive size. Switching to this mode will prompt to initialize and format the hard disks. This will not work to create a mirror set from existing hard drives with data. During a mode change if you have 2 drives in the HX4R, it will set the mode to RAID 1, for 4 drives in the HX4R, it will set the mode to RAID 10. NOTE: All data previously stored on the hard drive will be lost! Please back up all data to a separate storage before continuing. NexStar HX4R NexStar HX2R RAID 1 (10) RAID 1 ON ON NOTE: 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 Mode Configuration 14