Topic summary
RAID 4
Extracted from the Wikipedia article Standard RAID levels.
RAID 4
RAID 4 consists of block-level striping with a dedicated parity disk. As a result of its layout, RAID 4 provides good performance of random reads, while the performance of random writes is low due to the need to write all parity data to a single disk, unless the filesystem is RAID-4-aware and compensates for that.