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.
Advantage –
Good fault tolerance i.e.. ability of maintaining functionality even if one disk fails.
Disadvantage –
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.
Advantage –
In case of Error Correction it uses hamming code.
Disadvantage –
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. |
