Standard RAID levels
The standard RAID levels are a basic set of RAID configurations and employ striping, mirroring, or parity. The standard RAID levels can be nested for other benefits (see Nested RAID levels). The controller treats each drive as a stand-alone disk, therefore each drive is an independent logical drive. Concatenation does not provide data redundancy. Concatenation or Spanning of disks is not one of the numbered RAID levels, but it is a popular method for combining multiple physical disk drives into a single virtual disk. It provides no data redundancy. As the name implies, disks are merely concatenated together, end to beginning, so they appear to be a single large disk. Concatenation may be thought of as the reverse of partitioning. Whereas partitioning takes one physical drive and creates two or more logical drives, concatenation uses two or more physical drives to create one logical drive.
