This required a full stripe update for the tiniest change, leading to massive write amplification and latency. Modern RAID systems handle this by using larger block sizes; RAID.2 could not because of its bit-level granularity.
In a RAID 2 array, data is stripped down to the individual bit level and distributed across multiple data disks. Simultaneously, error-correction codes (Hamming codes) are calculated and written to separate, dedicated parity disks. raid.2
RAID.2 was optimized for (e.g., video streaming, scientific simulations). But for small, random I/O (e.g., a database transaction or a web server log), it was disastrous. To write a single byte (8 bits), a RAID.2 controller had to: This required a full stripe update for the
Modern hard drives now come with internal ECC capabilities, making the external Hamming code of RAID 2 redundant and unnecessary. Why Don't We Use RAID 2 Today? To write a single byte (8 bits), a RAID
In a typical three-disk data set, the first bit of a byte goes to Disk 1, the second to Disk 2, and the third to Disk 3. This requires all disks to spin in perfect synchronization to ensure the bits are read and written at the exact same moment.