RAID (Redundant Array of Inexpensive Disks) is a method of combining multiple hard drives for data redundancy in case of a hard drive failure.

The different types of supported RAID configurations are:

RAID 0

RAID 0 uses a technique called data striping. Multiple hard drives are combined to make one large volume. RAID 0 can read and write faster than a non-RAID configuration, since it splits the data and accesses both drives in parallel. RAID 0 does not provide any data redundancy. RAID 0 requires at least two hard drives.

RAID 1

RAID 1 mirrors or duplicates the content of one drive onto another equally sized drive. Mirroring provides optimal data integrity and immediate access to your data if one drive fails. RAID 1 allows you to use only half of the available capacity of your NAS device. RAID 1 requires at least two hard drives and must consist of an even number of drives.

RAID 5

RAID 5 provides the best balance of data redundancy and capacity. RAID 5 is the default RAID configuration for the Iomega® NAS. Like RAID 0, RAID 5 stripes all of the available drives into one large volume; however, the space equivalent to one of the hard drives will be used to store parity data. If one hard drive fails, your NAS will rebuild your data using the parity data. RAID 5 requires at least 3 hard drives. You may also use a RAID 5 configuration with hot spare, which reserves an additional hard drive that is swapped in immediately if a drive failure occurs. The total RAID capacity is the sum of all the hard drives minus the space of two drives. RAID 5 with hot spare requires at least 4 hard drives.

Non-RAID

In addition to RAID, you can also configure your NAS without using a RAID configuration. A non-RAID configuration, also referred to as JBOD (Just a Bunch Of Disks), does not allow any data redundancy and is slower than some RAID configurations.