RAID: Level 4

RAID 4 employs block-level striping and a dedicated parity disk to provide redundancy and performance improvements.

Unlike RAID 3, data is written in blocks, which allows for more efficient random access, making it suitable for mixed workloads.

The parity disk stores recovery data, enabling the system to rebuild information from a failed disk, but this configuration also risks a bottleneck during write operations.

Since all parity calculations are directed to a single disk, it may become a performance limitation under heavy write-intensive workloads.

This level is ideal for archival systems or environments with more reads than writes, such as document storage systems.

While offering better random access than RAID 3, RAID 4 is less commonly implemented due to the bottleneck introduced by its parity disk. Nevertheless, it laid the foundation for more advanced configurations like RAID 5 and RAID 6.