1. RAID 1:
RAID 1 is also called mirroring of data. Because it replicates the data from drive 1 to drive 2. One half of the drive is used to store the data and Another one is act as a mirror to the already stored data. This level provide 100% redundancy in case of failure.
Good fault tolerance i.e.. ability of maintaining functionality even if one disk fails.
It is Expensive Because extra drive is required for mirroring.
2. RAID 2:
RAID 2 consists of Bit-Level Striping. It records Error Correction Code (ECC) using hamming code parity. In this level each data bit in a word is recorded on separate disk and ECC codes of the data words are stored on a different set of disks.
In case of Error Correction it uses hamming code.
It has complex structure and high cost due to extra drive.
Difference between RAID 1 and RAID 2:
|SR.NO.||RAID 1||RAID 2|
|1.||RAID 1 stands for Redundant Array of Independent Disk level 1.||RAID 2 stands for Redundant Array of Independent Disk level 2.|
|2.||In RAID 1 technology, Disk Mirroring is used.||In RAID 2 technology, Bit-Level Striping is used.|
|3.||In RAID 1, one half of drive is used for storing data and another half is just a mirror for already store data||In RAID 2, each data bit in a word recorded on a separate disk and ECC codes are stored on different disk|
|4.||Good Fault tolerance as compared to RAID 2.||Fault tolerance is not so good.|
|5.||Hamming Codes are not used.||Hamming Codes are used for Error Correction.|
|6.||Extra Drive is required for mirroring.||Extra Drive is required for Error Correction.|