D-Link DNS-6040 [153/185] Raid 1 mirroring

D-Link DNS-6040 [153/185] Raid 1 mirroring
DNS-6040M/DNS-6040 User’s Manual
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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 spare disk. Should any disk in the array break down,

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