It does not guard against disk failure. A raid set up will not bring a failed drive back to life. Depending on the type of raid configuration used it may provide a "mirror" of the data set of the main drive. In the event of data corruption, the main drive data set can be "rebuilt" using the "mirror" data set. The advantage over the normal back up images is that it is up to date to the time the main set got corrupted. If a main drive fails the new drive can be loaded from the remaining good raid pair. Some raid configurations do nothing to safeguard data but provide a considerable disk speed boost during certain operations. It is also possible to construct a raid array that does both.
only use raid supported hdds in raid port.because if the hdd does not support raid u insert in raid port the hdd repair quickly reason raid port give more current to get data quickly so not supported raid hdds failed.
RAID (redundant array of independent disks; originally redundant array of inexpensive disks) is a way of storing the same data in different places (thus, redundantly) on multiple hard disks. By placing data on multiple disks, I/O (input/output) operations can overlap in a balanced way, improving performance. Since multiple disks increases the mean time between failures (MTBF), storing data redundantly also increases fault tolerance.