RAID and Subsystem Architectures RAID Configurations
RAID 5 – Block Striping
Unused space
Parity data File 3 File 2 File 1
Block B4 Block C1
Block A7 Parity
Block A1 Block A4
Reliability Read Performance
Write Performance
Block C2
Block B1 Block B5
Block A2 Block A5 Parity
Parity Block B6
Block A8 Block B2
Block A3 Parity
Block C3
Block A9 Block B3 Parity
Block A6 Parity
RAID 5 (block striping with distributed parity): Data is striped at the block level Parity information is striped across all disks Read performance is very good because data is spread across all drives Write performance is better than RAID 4 because there is no single parity drive to become a bottleneck, but performance is still inhibited by the parity calculation process