Redundant Array of Independent Disks, RAID is a combination of up to five (5) hard drives connected and set up in such a way to help protect or speed up the performance of a computer’s disk storage. RAID is commonly used on servers and high performance computers.
The Technics and concept applied in Raid is explained briefly below:
Spanning and software striping
This concept involves the computer in Splitting information and writing it across multiple physical disk drives. This method is popularly known as just a bunch of disc together . In striping, the computer is faster, it is also riskier. In the sense that if a drive fails, all data is lost since a section of every file would be missing or corrupted.
Alternatively , the concept of spanning allows multiple hard drives to behave as a single large drive. When the first drive becomes full, it simply overflows into the next. This method is useful because additional drives can be added easily without having to make major system modifications. Additionally, if a drive experiences a failure only a portion of the system’s data is lost
Duplication of data from one disk drive to another. In mirroring, we have Data stored twice by writing them to both the data drive and a mirror drive. If a drive fails, the controller uses either the data drive or the mirror drive for data recovery and continues operation
Duplicates the disk drive as well as the disk controller.Read data transactions are very fast while write data transactions are somewhat slower (due to the parity that has to be calculated). If a drive fails, you still have access to all data, even while the failed drive is being replaced and the storage controller rebuilds the data on the new drive.
in hot swapping , if a disk failed, it can be replaced and data can be placed back onto the disk drive while the remainder of the disk keeps working perfectly
Synchronization of the rotation of all disk drives in the array allowing information to be written all at once.