NFP Storage Manager 1.1 User’s Manual
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What is RAID?
efficiently transferred while assuring good quality, for example, in a
recording.
RAID 0 offers no mirroring or redundancy options. If one disk in the
array fails, the entire array is inoperable. RAID 0 is not fault-tolerant.
RAID 1 (mirroring)
In a RAID 1 array, disks are arranged in pairs. Data is always written
to both disks in a pair. This system is rather failsafe, but more
expensive than other solutions, since the user actually has to provide
twice the physical storage capacity. RAID 1 is often used in
environments with multiple users where safety is of great importance.
RAID 5
RAID 5 is the same as RAID 0, i.e. using multiple disks to emulate
one large virtual disk, but using parity data format to store redundant
information. While the user is writing data, RAID 5 scans the data and
stores redundancy information on a separate disk in the array. Parity
information is split and stored on different disks together with the
actual data. If one disk in the array fails, parity data on the safeguard
disk can still be used to rebuild the entire information.
In other words, in a RAID 5 array, you use one disk for redundancy
data, leaving you with n-1 disks available for actual data storage.
RAID 5 with hot spare
RAID 5 with hot spare is a RAID 5 configuration with one additional