RAID 0

RAID 0

The lowest designated level of RAID, level 0, is actually not a valid type of RAID. It was given the designation of level 0 because it fails to provide any level of redundancy for the data stored in the array. Thus, if one of the drives fails, all the data is damaged.

RAID 0 uses a method called striping. Striping takes a single chunk of data like a graphic image, and spreads that data across multiple drives. The advantage that striping has is in improved performance. Twice the amount of data can be written in a given time frame to the two drives compared to that same data being written to a single drive.

Below is an example of how data is written in a RAID 0 implementation. Each row in the chart represents a physical block on the drive and each column is the individual drive. The numbers in the table represent the data blocks. Duplicate numbers indicate a duplicated data block.

Thus, if the 6 blocks of data above constitute a single data file, it can be read and written to the drive much faster than if it were on a single drive. Each drive working in parallel could read only 3 physical blocks while it would take a single drive twice as long because it has to read 6 physical blocks. The drawback of course is that if one drive fails, the data is no longer functional. All 6 data blocks are needed for the file, but only three are accessible.

Advantages:

• Increased storage performance
• No loss in data capacity

Disadvantages:

• No redundancy of data\

source: about.com