The Different Levels of Data Protection Under RAID

The redundant array of independent disks, better known as RAID in the technology world, provides a method of data storage on hard disks which is designed to improve performance as well as redundancy to avoid data loss. RAID methodologies total 10 distinct designs of RAID servers, ranging from the most basic which has no redundancy to a level 10 which has some of the best protection possible. These levels include:

RAID 0
The most basic level of data storage, the RAID 0 level has no backup level in case there’s a data loss. The setup does improve performance, which makes it popular for small business servers.
Minimum number of drives required: 2

RAID 1
In this array the data is written simultaneously to two disks, storing data in a mirror-type approach. When the data needs to be retrieved again, one or the other drive produces the information for the request. When the data is changed, however, the change happens again on both disks simultaneously. Minimum number of drives required: 2

RAID 2
The RAID 2 approach is a theoretical design using Hamming-code parity via synchronized disk rotation. In practice, this design is not used. Minimum number of drives required: not applicable.

RAID 3
Because the RAID 3 design saves a sequential byte of data across multiple drives, with parity tracked and calculated on a separate drive, the storage splits the data into multiple locations. While this approach is used, it is not common due to the complexity of installation.
Minimum number of drives required: 3

RAID 4
With a single drive all parity data involved is written on one drive disk. While multiple disks can be used under RAID 4, each one works on its own without any dependency on the other.
Minimum number of drives required: 3

RAID 5
Requiring a minimum of three disks to be installed, a RAID 5 approach maintains parity on data stored but requires all drives involved to be operating at any given time. Only one drive can be tolerated as a failure at any given time.
Minimum number of drives required: 3

RAID 6
Allowing two failed drives to occur at a given time, RAID 6 groups can be larger with a greater fault tolerance. However, because of the level of redundancy, recovery is far stronger when data is lost due to one disks failure in the set.
Minimum number of drives required: 4

RAID 10
RAID 10 or RAID 1+0 provides a complete mirroring of data across every disk in a set and a secondary disk matching each first one. This provides the greatest amount of redundancy for data protection.
Minimum number of drives required: 4

All of the RAID options above are available with our Advatronix® Cirrus™ 1200 server.