User manual
23
TeraStation uses RAID (“Redundant Array of Independent Disks”) technology to control the four
hard drives in your TeraStation. RAID may be congured several ways:
RAID 0 - All four drives are combined into one large, fast drive, giving the maximum capacity
for your TeraStation. This size is the one listed on your TeraStation’s box and shows the total
capacity of the TeraStation with no data used for redundancy. RAID Spanning is fast and
efcient, but with no redundancy, if one hard drive fails, all data on the TeraStation is lost.
RAID 1 (mirroring) - Hard drives are arranged in mirrored pairs. Each half of the pair reads and
writes exactly the same data. This costs you half the total capacity of the array, but provides
excellent redundancy. If a hard drive fails, the mirror continues to supply data, so you may work
on normally. You may replace the damaged or defective drive at any time, and normal RAID 1
mirroring will then be automatically restored.
RAID 5 (parity) - All drives in a RAID 5 array reserve part of their data space for parity
information, allowing all data to be recovered if a single drive fails. The parity information takes
up about one hard drive’s worth of space, so if you set up all four drives in the TeraStation as
a RAID 5 array, your usable capacity will be about 3/4 of the total capacity of the TeraStation.
This is the default conguration.
RAID 10 - Combines RAID 1 and RAID 0 for a fast, secure array. Half of the TeraStation’s total
capacity is used for redundant information.
RAID Arrays