RAID 2 A RAID 2 requires a minimum of 2 hard drives to configure. Each bit of data is written to a data disk (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. In certain instances a RAID 2 array can recover from multiple and simultaneous hard drive failure. The entry level costs for RAID 2 are extremely high, making it not commercially viable. A RAID 2 performs 'on the fly' error corrections.
