D-Link DNS-33 User Manual page 48

Section 3 - Configuration
RAID, short for Redundant Array of Independent Disks, is a combination of two or more disks with the aim of providing
fault tolerance and improving performance. There are several different levels of RAID, with each providing a different
method of sharing or distributing data amongst the drives. The DNS-323 supports RAID levels 0 and 1.
RAID 0 RAID 0 provides data striping, which spreads
out blocks of data over both drives, but does not
provide data redundancy.
Although performance is improved, the lack of
fault tolerance means that if one drive fails, all
data in the array will be lost.
RAID 1
RAID 1 provides mirroring over both disks, with
the same read/write speed of a single disk. A
RAID 1 array can only be as large as it's smallest
member disk.
Because the data is stored on both disks,
RAID 1 provides fault tolerance and protection,
in addition to performance advantages.
D-Link DNS-33 User Manual
What is RAID?
RAID 0
RAID 1