1. What is a RAID 6 Calculator?

Definition: This calculator estimates the usable storage capacity in a RAID 6 array based on the number of drives and their individual sizes.

Purpose: It helps IT professionals and system administrators plan storage arrays with double parity protection.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \text{Capacity} \) — Usable storage capacity (TB)
• \( N \) — Number of drives in the array
• \( \text{DriveSize} \) — Size of each drive (TB)

Explanation: RAID 6 uses two drives for parity (fault tolerance), so the usable capacity is the remaining drives multiplied by their size.

3. Importance of RAID 6 Capacity Calculation

Details: Proper capacity planning ensures you allocate sufficient storage while maintaining dual-disk fault tolerance for critical data protection.

4. Using the Calculator

Tips: Enter the number of drives (minimum 3) and the size of each drive in TB. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why subtract 2 drives in RAID 6?
A: RAID 6 uses two drives for parity information, providing protection against two simultaneous drive failures.

Q2: What's the minimum number of drives for RAID 6?
A: RAID 6 requires a minimum of 4 drives, though some implementations allow 3 drives (with very limited capacity).

Q3: How does RAID 6 compare to RAID 5?
A: RAID 5 uses single parity (N-1 capacity) while RAID 6 uses double parity (N-2 capacity) for better fault tolerance.

Q4: Does this account for different drive sizes?
A: No, for mixed drive sizes, capacity is limited by the smallest drive in the array.

Q5: What about formatting overhead?
A: This shows raw capacity. Actual usable space will be slightly less due to filesystem overhead.