1. What is a RAID 5 Size Calculator?

Definition: This calculator estimates the usable storage capacity in a RAID 5 array based on the number of drives and their individual sizes.

Purpose: It helps IT professionals and system administrators plan storage capacity when implementing RAID 5 configurations.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: RAID 5 uses distributed parity, requiring the equivalent of one drive's capacity for redundancy, hence (N-1) × DriveSize.

3. Importance of RAID 5 Size Calculation

Details: Proper capacity planning ensures you allocate sufficient storage for your needs while maintaining fault tolerance through parity.

4. Using the Calculator

Tips: Enter the number of drives (minimum 3) and the size of each drive in TB. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why does RAID 5 require N-1 drives worth of space?
A: RAID 5 uses distributed parity across all drives, which consumes the equivalent capacity of one full drive.

Q2: What's the minimum number of drives for RAID 5?
A: RAID 5 requires a minimum of 3 drives to implement distributed parity.

Q3: How does drive size affect the calculation?
A: In RAID 5, all drives should ideally be the same size. If different, the array will use the smallest drive's capacity for all.

Q4: What about RAID 5E or RAID 5EE?
A: These enhanced versions have different capacity calculations and aren't covered by this basic calculator.

Q5: Does this include formatting overhead?
A: No, the calculation shows raw capacity. Actual usable space will be slightly less due to filesystem overhead.