What is RAID LEVEL

RAID LEVEL 0
RAID 0 is used to boost a server’s performance.
It’s also known as “disk striping.” With RAID 0, data is written across multiple disks. This means the work that the computer is doing is handled by multiple disks rather than just one, increasing performance because multiple drives are reading and writing data, improving disk I/O. A minimum of two disks is required. Both software and hardware RAID support RAID 0 as do most controllers. The downside is that there is no fault tolerance. If one disk fails then that affects the entire array and the chances for data loss or corruption increases.

Graphical representation of the RAID layout:

Raid Level 0

RAID LEVEL 1

This is useful when performance read or reliability is more important than data storage capacity.

Such an array can only be as big as the smallest member disk. A classic RAID 1 mirrored pair contains two disks over a single disk. Since each member contains a complete copy and can be addressed independently, ordinary wear-and-tear reliability is raised by the power of the number of self-contained copies.

Graphical representation of the RAID layout:

Raid Level 1

What is RAID LEVEL 2

A RAID 2 stripes data at the bit (rather than block) level, and uses a Hamming code for error correction.

The disks are synchronized by the controller to spin at the same angular orientation (they reach Index at the same time), so it generally cannot service multiple requests simultaneously. Extremely high data transfer rates are possible. This is the only original level of RAID that is not currently used.

All hard disks eventually implemented Hamming code error correction. This made RAID 2 error correction redundant and unnecessarily complex. This level quickly became useless and is now obsolete. There are no commercial applications of RAID 2.

Graphical representation of the RAID layout:

Raid Level 2