RAID Storage Reliability Simulation
Probabilistic Modeling of Data Integrity & Disk Failure
Redundant Array of Independent Disks (RAID) is a fundamental technology for balancing performance and data safety. However, not all RAID levels are created equal when it comes to reliability. As disk capacities increase, the probability of a Unrecoverable Read Error (URE) during a RAID rebuild becomes a critical factor in system design.
RAID 0 (Striping)
Zero redundancy. Reliability decreases exponentially with every added disk. If any drive fails, all data is lost.
RAID 1/10 (Mirroring)
Full redundancy. Data is duplicated across pairs. Survives the loss of 50% of disks if failures occur in different mirrors.
RAID 5/6 (Parity)
Distributed parity. RAID 5 survives 1 disk failure; RAID 6 survives 2. Capacity vs. Reliability sweet spot.
RAID Parity Reconstruction Simulator
XOR-Based Data Recovery
Click disks to simulate failures. RAID 5 uses single parity (P) via XOR, tolerating 1 disk failure. RAID 6 adds a second parity (Q) using Reed-Solomon codes, tolerating 2 simultaneous failures. During rebuild, the array is vulnerable—if another disk fails before reconstruction completes, all data is lost.
Interactive RAID Simulator
Model your storage array by selecting the RAID level, disk count, and individual disk reliability (MTBF). The simulator will calculate the cumulative system reliability and the probability of data loss over the specified mission time.
Array Config
Distributed Parity - Balanced capacity and safety (1-disk fault tolerance).
Array Topology: RAID 5
RAID MTBF Calculation
The calculation uses the survival probability of independent components. Note that real-world reliability is often lower due to "correlated failures" (disks from the same batch failing simultaneously) and the performance penalty of rebuilding an array which puts extreme stress on surviving drives.
The Rebuild Paradox
Modern reliability engineering warns that RAID 5 is increasingly risky for high-capacity drives (12TB+). The time required to rebuild a failed array and the mathematical probability of a second drive failing or a URE occurring during that window significantly threatens data integrity.