| RAID Level: |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
10 |
53 |
0+1 |
RAID 2: Hamming Code ECC  Each bit of data word is written
to a data disk drive (4 in this example: 0 to 3). Each data word has its
Hamming Code ECC word recorded on the ECC disks. On Read, the ECC code
verifies correct data or corrects single disk errors. |
Characteristics/Advantages "On the fly" data error
correction Extremely high data transfer rates possible The higher the data transfer rate required, the better the ratio of
data disks to ECC disks Relatively simple controller design compared to RAID levels 3,4 &
5 |
Disadvantages Very high ratio of ECC disks to
data disks with smaller word sizes - inefficient Entry level cost very high - requires very high transfer rate
requirement to justify Transaction rate is equal to that of a single disk at best (with
spindle synchronization) No commercial implementations exist / not commercially
viable |